Published using Google Docs
CURRENT DRAFT Style Guide - Fall 2023

Resources for the Future Style Guide

Contents

Introduction

Numbers

Dates and Times

Dates

Times

Mathematics and Equations

Units and Measurement

Systems of Measurement

Numerals and Unit Abbreviations

Punctuation

Titles, Subtitles, and Headings

Capitalization

Key capitalization reminders

Headline Capitalization

Geographic Regions and Descriptors

Language Referring to Black and Indigenous Groups and People of Color

Italics and Boldface

Interview Format

Footnotes and Endnotes

Lists

Figures and Images

Tables

Line Breaks and Hyphenation

Word Choice and Usage

Abbreviations, Acronyms, and Initialisms

Compound Words

Latin Phrases

Word Choice

Gender-Neutral Language

References: Author-Date System

Preparing a Reference List

References to Books

References to Periodicals

Assembling the Reference List

Preparing Text Citations

Elements of a Text Citation

Determining the Correct Text Citation

Incorporating the Text Citation into the Text

Table of Reference Samples

Appendix A: Lists and Tables

RFF Specialized Word List

Units of Measure

Currency Abbreviations

Chemical Compounds

Agencies and Organizations

US Government Agencies

Other Agencies and Organizations

Laws, Legislation, and Treaties

Appendix B: Editing Guidelines for Freelancers

Quick Listicle: A “Cheat Sheet” of the Most Important Takeaways from the Chicago Manual of Style


Introduction

The RFF style guide serves as a quick and helpful definitive reference, providing some guidelines for authors and editors of RFF publications and Resources editorial content. What follows is an organized collection of the most frequent issues of writing style addressed at RFF. (Note that the “Quick Listicle” is an abbreviated guide that highlights notable style guide rules; it may serve as a good starting point for RFF style.)

RFF style primarily adheres to the Chicago Manual of Style. For any questions not specifically addressed in this style guide, refer to the Chicago Manual for the answer.

Where the RFF style specified here differs from the Chicago Manual of Style, conform to RFF style. For questions related to spelling, use the first spelling or main listing in Merriam-Webster’s 11th Collegiate Dictionary.

RFF style generally follows the guidance of these reference works:

To point out any errors or useful additions to the RFF style guide, please contact the communications team. Check in with the communiceratureations team if further questions arise, and please be flexible.

RFF style guide key:

Numbers

Spelling Out Numbers: In text, spell out whole numbers from zero to nine; use Arabic numerals for all other numbers, except when they start a sentence. In tables and figures, use only Arabic numerals. For usage with units of measure, see that section below.  

Avoid mixing numerals and words: one out of five or 5 out of 101. Within a given sentence, all numbers should be either numerals or words.

Ordinal Numbers: Spell out up to nine (first, second, third, . . . ). For larger numbers, use the shortened form (10th, 11th, . . . 101st, 102nd, . . . ). Despite autocorrections by Microsoft Word, do not put the suffix letters in superscript type: 53rd not 53rd. Spell out ordinal names of centuries: nineteenth century, twentieth century.

Thousands, Millions, and Billions: Use the comma to indicate thousands in countable items with four or more digits (7,800; 103,321; 3,498,669). Do not use a thousands comma in page numbers or decimal places. For round numbers, generally use a numeral along with the word million or billion (4 million, 10 billion).

Number Ranges: Number ranges should use en dashes (e.g., 1–10). Include all numbers in a range, except for some types of dates (see the section on Dates below). With continuing numbers—such as dates, times, and page numbers—use an en dash to signify up to and including (or through). For example, The years 1993–2000 were heady ones for the computer literate.

Avoid mixing dashes and prepositions: For parallel construction, the word to, never the en dash, should be used if the word from precedes the first element in such a pair. Similarly, and, never the en dash, should be used if between precedes the first element. For example:

Ratios: In text, use the word to: a 13-to-2 ratio or a ratio of three to one (hyphenate only when before a noun). In tables and figures, you may use a colon instead of to, e.g., 10:1.

Decimals: Be as consistent as possible as to the number of decimal places used, especially in tables; for instance, within a column or type of measurement, it is best to use the same number of decimal places. However, do not add zeroes simply to fill up decimal places; 1.620 is a more precise number than 1.62, so should only be used when precision is warranted by the data. Do put a zero in front of a decimal number less than one. For example, Among those surveyed, 5.3 percent favored product A, while 0.6 percent preferred product B.

Matrices: Use bold to indicate matrices and vectors in mathematical text.

Percentages: In text, use numerals and spell out the word percent: 10 percent. (Note: Exceptions may be made for working papers, which can often be fairly technical. The percent sign may be used throughout the text, but a mix of the two usages is not permitted.) In instances where length is particularly constraining, such as graphics, layouts, and social media, the % symbol is acceptable if spelling out percent doesn’t fit within the constraints of the medium.

Use the noun form, percentage, when referring to the numerical value (i.e., when a number is not given). For example, The percentage of Americans who live in poverty increased this year.

Money and Currency: For 1988 dollars, use 1988$ or dollar year 1988 and not $1988. For dollar amounts where you need to specify US dollars, use US$5,000. When it is necessary to specify both the dollar year and the currency’s country, put a space between the dollar year and the currency. For example, The current tax is $3.40 (2019 US$) per gallon. 

For ranges of currency, use the currency symbol for each instance of a specified value. For example, $30–$40 billion and not $30–40 billion. Where the range may cause some confusion, specify the magnitude at both ends of the range, as in $30 billion–$40 billion.

For other currency symbols and abbreviations, please see the Currency Abbreviations section.

Dates and Times

Dates

RFF prefers the American style for dates (month day, year), although the European style (day month year) is permissible as long as a publication is internally consistent.

Decades: 1990s not 1990’s. The two-digit style (class of ’90) should only be used in informal contexts. Spelling out the decade (the nineties) is OK, but please be consistent within each document.

Centuries: Spell out ordinal names of centuries: nineteenth century, twentieth century.

Fiscal years, FY:

Times

Time of day is generally given in civilian, rather than military, style. The time should be given in Arabic numerals, followed by a space, and then a.m. or p.m. in lowercase letters: 9:00 a.m., 10:30 p.m. See the Units of Measure section for the use of numerals with units of time.

When writing time ranges, connect both times with an en dash and list both the hour and minute digits. For example, 8:00–9:30 a.m. Include a.m. or p.m. for the start time if the time range spans noon, i.e., if the tame range includes both an a.m. time and a p.m. time. For example, 8:00 a.m.–1:00 p.m., 11:00 p.m–1:00 a.m. Note that noon is 12:00 p.m. and midnight is 12:00 am. If using a time range to give information about an RFF event, include Eastern Time after the time range. For example, 1:00–3:00 p.m. Eastern Time. Indexed production of refined lithium – brine lithium + hard rock lithium (indexed metric tonnes of lithium carbonate equivalent)

Mathematics and Equations

Inline Math: Mathematical expressions that appear in running text should be written so they use a single baseline—that is, so they do not affect the line spacing of a paragraph. For example, in running text, the inline equation (a2 + b2)/c2 is better than  .

Display Math: Mathematical expressions that cannot be conveniently written on a single baseline or that should be graphically separated for the reader’s convenience appear on a separate line from the text that precedes and follows it.

Numbering Equations: The occasional display equation need not be numbered. However, in the case of many equations, or when the text makes reference to equations, numbering is appropriate. Equations are numbered beginning with 1. Equation numbers should appear in parentheses and flush with the right margin. Text references should be lowercase and have parentheses around the number: equation (1).

Punctuation and Display Math: When part of a regular sentence, equations should be punctuated as such.

Units and Measurement

Systems of Measurement

Two systems of measurement are in common use today; either is acceptable in RFF work, depending on the subject and audience. One set, metric or SI (Système Internationale), uses units such as meters, kilograms, and degrees Celsius. Metric units are generally preferred, especially when the subject is strongly scientific or technical or when the focus/audience is international. The other set, called imperial, uses units such as feet, miles, pounds, and degrees Fahrenheit. Imperial units may be used when the subject and the intended audience are nontechnical.

For most RFF publications, it is not necessary to include measurements in both sets of units. Select the one that is most appropriate and apply it consistently.

When discussing temperatures, use the degree symbol and the metric or English unit (as appropriate), with no spaces in between: between 3°F and 8°F, 3°C–7.

Numerals and Unit Abbreviations

RFF’s style guidelines for the use of numerals and abbreviations with units of measure are somewhat flexible, provided that each document is internally consistent and the choice of styling relates to the technical content of and audience for a particular document. (Copyeditors should determine a style for a given document in consultation with an RFF editor.) The following points should direct style choices.

Units of Time: Always spell out the units second, minute, hour, day, month, and year. Spell out whole numbers from zero to nine; use Arabic numerals for all other numbers, except when they start a sentence. Avoid mixing words and numerals.

Units of Physical Quantities: In documents that do not include many measurements of physical quantities (i.e., those that are nonscientific/nontechnical in nature or are aimed at a nontechnical audience), spell out the units. If a particular unit appears frequently, the abbreviation can be noted in parentheses at the first usage and used thereafter.

In documents that include many measurements of physical quantities (i.e., those that report on experiments and results, are scientific/technical in nature, and are directed at a scientific audience), abbreviate the units, but spell out the first time, followed by the abbreviation in parentheses.

Common base units (such as the common units in the metric system) and derived units (base units with a prefix indicating a power of 10) may be used in their abbreviated forms. All numbers with units should appear as Arabic numerals.

Units in Tables and Figures: Units may be abbreviated; uncommon unit abbreviations should be explained in a note. Use Arabic numerals for all numbers.

Punctuation

RFF follows the Chicago Manual of Style almost without exception for punctuation. Here are several key points:

Commas:

Periods:

Use only one space after a period at the end of a sentence, as well as after a colon.

Apostrophes and Possessives: The possessive of most singular names and nouns is formed by adding an apostrophe and an s. The possessive of plural nouns (except for a few irregular plurals that do not end in s; e.g., children) is formed by adding an apostrophe only.

For possessive nouns that are plural in form and singular in meaning, when the singular form of a noun ending in s is the same as the plural (e.g., economics, politics, and species), the possessives of both the singular and plural forms require the simple addition of an apostrophe only. For example, politics’ true meaning; economics’ foundational texts; try not to destroy a species’ critical habitat; the United States’ intention; or the National Academy of Sciences’ new policy. If ambiguity threatens, then use of to avoid the possessive: the true meaning of politics. (See the “Possessive of nouns plural in form, singular in meaning” section of the Chicago Manual of Style.)

When making an italicized term plural or possessive, the s or ’s should be set in roman type; e.g., the Washington Post’s.

Ellipses: Used to indicate missing text. Use the special character from the symbol font () instead of three periods (... or . . .). If an ellipsis falls in the middle of a sentence, put spaces on each side (e.g., first quoted phrase … second quoted phrase). If it falls at the end of a sentence, include a period, then a space, the ellipsis, and another space. Do not use ellipses before the first word or after the last word of a quotation, even if the beginning or end of the original sentence has been omitted.

(Note: This convention is desirable because formatting the periods of ellipses as a single character means that if the ellipses land at or near the end of a line of text, one or a couple of the periods won't get cut off and end up on the subsequent line of text. Ellipses written as three periods with a space on either side of each period can lead to odd line breaks and orphaned periods.)

See the “Ellipses at the ends of deliberately incomplete sentences” and “Ellipses for the omission of whole or partial paragraphs” sections of the Chicago Manual of Style for exceptional circumstances.

En Dash: Use an en dash (–) to indicate ranges (e.g., pages 249–265 and the May–October break between magazine issues), as well as before open compounds (such as pre–World War II). To type an en dash in Word, select it from the expanded character set found under Insert > Symbol; in Windows, hold down the Alt key and type 0150 on the number keypad; on a Mac, you can hold down the Option key while pressing the minus key.

Em Dash: Use an em dash (—) to set aside words or clauses in a sentence. Use em dashes sparingly and mainly for emphasis. When setting off a short phrase with no interior punctuation, a pair of commas will do as well. To set aside examples or longer lists, use parentheses. To type an em dash in Word, select it from Word’s expanded character set found under Insert > Symbol; in Windows, hold down the Alt key and type 0151 on the number keypad; on a Mac, you can hold down both the Option and Shift keys while pressing the minus key.

Em Dashes in Reference Lists: Use three em dashes in reference lists to indicate a repeated author name.

Hyphens: For questions related to hyphens, see the Chicago Manual of Style hyphenation table.

Quotation Marks: When it comes to putting periods and commas inside or outside quotation marks, RFF uses American (or aesthetic) style—that is, periods and commas go inside quotation marks, except in rare instances when doing so could lead to confusion or misunderstanding. Colons and semicolons go outside the quotation mark. Question marks and exclamation points follow logical style and go inside or outside, depending on whether they are part of the quotation. All quotation marks should be double quotation marks, except for quotations within quotations, which are set apart with single quotation marks.

Titles, Subtitles, and Headings

Titles for discussion papers, journal articles, book chapters, and books should be descriptive of the material under discussion. Subtitles may be used to help focus the title, but the title should be able to stand alone. Avoid excessive cuteness or cleverness in titles. Titles should be fairly short: no more than five or six words for books and chapters, no more than ten for papers and articles. Subtitles can add five or six more words. (Note that these are guidelines, not hard-and-fast rules.)

A system of subheadings should be used to organize written materials. For shorter pieces (under 15 pages), one or two levels of subheadings should be sufficient. For longer pieces, three—or possibly four—levels of subheadings may be used. (More than four levels of subheadings become confusing for readers.) Subheadings should be fairly short and descriptive of the material that follows. Since they function as organizing aids for readers and as elements of graphical interest, it is a good rule of thumb to try to have one subheading appear every page or two.

A few rules of thumb: Never type titles, subtitles, or subheadings in all capitals. Follow rules under Capitalization, below, or use this handy tool (be sure to select Chicago). Avoid punctuation at the end of titles, subtitles, and subheadings.

Note to authors: Please format the levels of subheadings consistently in such a way that the RFF communications staff members and freelance copyeditors can distinguish them.

Capitalization

Key capitalization reminders

Rules for capitalization follow the Chicago Manual of Style.

Headline Capitalization

For titles, subtitles, headings, and subheadings, always use headline capitalization, as listed here. Confused? Use this handy tool. (Be sure to select “Chicago.”)

Geographic Regions and Descriptors

In general, capitalize specific names of regions, such as the Midwest and the North, but do not capitalize directional geographic descriptors, such as to the north unless referring to specific regions, such as the Midwestern United States See more specific examples below and on the RFF Specialized Word List.

Capitalize Regions of the United States: New England, the Northeast, the Mid-Atlantic, the South, the Southeast, the Midwest, the Southwest, the West, the Northwest, the Pacific Northwest, the Far West, the East/West Coast, Southern California

Capitalize Regions of the World: North Atlantic, Southeast Asia, the Middle East, the Near East, East/West Africa, sub-Saharan Africa

Do Not Capitalize Directional Geographic Descriptors: eastern United States, eastern Europe, southern Asia, western Europe, heading north, to the north, northerly

States and Cities: Do not capitalize federal, state, local, municipal political divisions when they precede the name (the state of California, the city of San Francisco) except when part of the official title of a specific governmental body (She works for the State of California or the City of San Francisco, but I forget which). These are always capitalized when they follow a name. For example, New York City, Washington State.

Language Referring to Black and Indigenous Groups and People of Color

Capitalize adjectives that refer to communities of color or cultural or ethnic groups: Black communities, Asian American communities, Indigenous peoples. Do not capitalize other similar adjectives that refer to race. For example, white people or brown communities. For more information, see this article from the New York Times. 

Native nations: In general, refer to Indigenous peoples who are native to the geography of the United States as Native nations. When referring to a specific Native nation, use the name with which the Native nation refers to itself. Capitalize “Tribal” and “Tribe” when using the word in the context of Native nations. For more information, see this guide from the Native Governance Center.

Legal language: When a government representative or agency references a group in a statute or legal document (e.g., in a law or regulation) in a way that contradicts the RFF Style Guide, use the term as stated in the official document and include a footnote to explain that the term is a legal term, citing the relevant statute(s) or document(s). For example, The federal guidance for the Low-Income Communities Bonus Credit Program references “Indian Land,” which has a special definition under the Energy Policy Act of 1992.

Italics and Boldface

Italics: Use italics to indicate titles of documents, books, or journals; variables (in mathematical text); words that are being defined (Note: use italics in reports and other publications, bold in explainers, and quotation marks in editorial products); and foreign words that have not become commonplace in English. Words and abbreviations that should not be italicized include the following: per se, vis-à-vis, et al., e.g., i.e., ex post, ex ante, in vivo, ab initio. Any term listed in Merriam-Webster should not be italicized.

Emphasis: Avoid using italics or boldface for emphasis, except to call out important terms that will be defined.

Mathematics: Use bold to indicate matrices and vectors in mathematical text.

RFF Event Titles: Individual event titles should be in quotation marks, not italics. Event series names should be in title case but not italicized. Conference names should be in title case but not italicized.

Report Series: Individual report titles should be in title case and italicized. Report series names should be in title case and italicized. For example, Climate Insights 2020: Natural Disasters and Climate Insights 2020 series and Fairness for Workers and Communities in Transition report series.

Explainer Series: Individual explainer titles should be in title case and quotation marks, not italics. Explainer series names should be in title case, not italics. For example, “Federal Climate Policy 105: The Industrial Sector” and Federal Climate Policy Toolkit explainer series.

Newsletters: Italicize the names of newsletters. For example, On the Issues newsletter.

Media Outlets: Italicize the names of media outlets that are available in print, but not those published only online. Most often, neither capitalize nor italicize the in the name of a media outlet or publication. For example, Associated Press, Automotive News, Axios, Barron’s, Bloomberg, Business Insider, Car and Driver, CNN, E&E News, Fast Company, Financial Post, Financial Times, Forbes, Heatmap, the Hill, the National Journal, the New York Times, Politico, Quartz, Reuters, S&P Global, the Wall Street Journal

Interview Format

Some articles published on the website or in print will take the form of a Q&A, interview, or conversation, any of which may involve two or more people. Sometimes Resources magazine conducts the interview (rather than a specific person who gets a byline), and sometimes the interviewer will be a named individual. Please format the text in these interview-style articles by referring to the guidelines below.

Resources as interviewer with one guest:

Resources as interviewer with two or more guests:

Resources Radio interview on the website:

Resources Radio interview in the print/digital magazine:

For other variations on interview-style articles (e.g., a Resources Radio interview with one host and multiple guests), draw from the guidelines above to maintain a consistent style.

Footnotes and Endnotes

Footnotes are notes that appear at the bottom of the page on which the note callout appears. Endnotes are notes that appear at the end of a paper, chapter, or book. You may use either the footnote or endnote feature in Word, but the appearance of the notes in published form will depend on the publication type and template.

Notes in journal articles and books will follow the publisher’s preference. Generally, footnotes are more costly, complicated, and time-consuming to produce in typeset text than endnotes, so most commercial publishers mandate the use of endnotes. Even in documents with endnotes, occasionally an unnumbered footnote is used, such as on the opening page of a chapter or article to note the author’s affiliation or acknowledge assistance.

Content of foot-/endnotes: An excessive number of notes is an inconvenience to readers, who must keep looking up and down or flipping back and forth. Authors should carefully consider the added value that each note will provide to readers in deciding whether it is necessary. The author-date system of references removes nearly all source citations from the notes. Therefore, for many RFF publications, notes should contain explanatory or clarifying information only. Exceptions can be made for legal scholars. Digressive footnotes are discouraged in RFF publications. If information is not important enough to include in the text, chances are that it may not be worth a note.

Lists

Parallelism: Items within a list must be grammatically parallel (for example, all nouns, all verbs in the same tense, all participles, or all complete sentences).

Run-In Lists: When several items appear as a run-in list—meaning that it fits within a paragraph, rather than as a bulleted or numbered list—generally, separate the items with commas (using the serial/Oxford comma). If any one of the items has a comma within it, then separate all the items with semicolons. For example:

The program encourages firms to develop less toxic substitutes for highly toxic chemicals, reformulate products, and redesign production processes. Our analysis considered major US pollution legislation, including the Resource Conservation and Recovery Act; the Clean Water Act; and the Comprehensive Environmental Response, Compensation, and Liability Act.

Sometimes a run-in list is simply too difficult to follow without aids. Lowercase letters in parentheses can be used to distinguish among list items, if necessary. For example:

Given the choice of (a) selling a permit and paying tax on capital gains accrued to date and then investing the sale proceeds or (b) holding the permit in expectation of further capital gains, which will be taxed only when the permit is finally sold, existing permit holders tend to prefer to defer permit sales.

Vertical Lists: Use a vertical list when the separation of points from normal text will be an aid to the reader or there’s some other rationale to do so.

A vertical list is best introduced by a grammatically complete sentence, followed by a colon. Note that it is not grammatically correct to introduce a list with an incomplete sentence followed by a colon, such as The list includes: (If a list is a complete sentence, then no colon is needed; see Example 3 below.)

Two basic types of vertical lists include the following: unordered (in which the items are introduced by a bullet or other such marker or by nothing at all) and ordered (in which items are introduced by numbers or letters). Unless the items consist of complete sentences, each item carries no end punctuation and each can usually begin lowercase.

If each list item is a complete sentence, it should be followed by a period; if not, no period should be used.

In some cases, a vertical list may form a complete sentence. In this case, the lead-in sentence should not be followed by a colon, and each list item should end with a comma or semicolon. (See Example 3 below.)

List Example 1: List items are not complete sentences. The list itself is not a complete sentence.

Your application must include the following documents:

List Example 2: List items are complete sentences. The list itself is not a complete sentence.

Highlights of the authors’ findings are as follows:

List Example 3: The entire list is a complete sentence, formatted as a vertical list for clarity.

The grocery list included

For more help with lists, see the “Lists and Outline Style” section of the Chicago Manual of Style.

Figures and Images

Illustrations should be used to help readers understand the material being presented in text; charts and graphs can be a very efficient way of conveying data or the implications of data.

For RFF Publications: When submitting a paper to the RFF communications team for publication, please provide either a spreadsheet of the underlying data or an editable image whenever possible. To provide an editable image, export from the software used to create the figure as a .pdf, .svg, or .eps file. Do not export as a PDF from another file type, such as Word or PowerPoint; this will not produce an editable image. The communications team may reach out to you for a different file type at times. The communications team can also help create figures from scratch.

For External Submission (e.g., books and journal articles): If you are preparing figures or other visual materials for a book or journal, find out what the publisher requires in terms of format and design, and then reach out to the communications team for assistance as needed.

Style for Figures: All elements of a figure should be clearly labeled, in text-sized type, with an initial capital letter. Lines or bars of a graph must be labeled in the graph or in a legend box. Legends generally appear above or below the figure. Within reason and when possible, the communications team will re-create all figures in major RFF publications to align with the RFF brand.

Figure Titles and Captions: A brief title should appear above every figure. Generally, the titles should be typed using headline capitalization and should not have a period at the end. However, they may be written as full-sentence descriptions, in which case they should have an initial capital letter only and include a period at the end. Within a given paper or chapter, these two types of titles may not be mixed. Parentheticals should be set in sentence style even if the main title is in headline style.

Figures may also have notes or source information, which appears in a small font beneath the figure and with Source: and Notes: in italics (and in that order).

Figure titles should be preceded by the word Figure followed by the figure number (or, in books, by the chapter number, a hyphen, and the figure number), then a period and space, then the title. Placement of figure titles or captions in a document laid out by a designer is at the designer’s discretion.

Reproducing Previously Published Figures: If you are reproducing a figure that was previously published in a copyrighted form, you must obtain permission in writing from the publisher to reproduce the figure. Even if you redraw a figure, if it is substantially the same—meaning, roughly, 75 percent the same—you must get permission. Figures in most government documents are not under copyright and may be reproduced without permission; RFF figures may be freely reproduced in other RFF documents. In all cases, the source must be identified.

References to Figures: Every figure that appears must be referenced in the text, and figures must be numbered in the order in which they are mentioned. Use the word Figure and the figure number. Acceptable ways to refer to a figure include the following:

Photo Credits: By default, include photo credits for all photos and illustrations. The correct format is to include first the name of the photographer or account, then the company or stock photo site, separated by spaces and forward slash. For example, PhotoAccount123 / Getty Images.

Credits for cover photos on publications should be located after the “About the Authors” section, in a section titled “About the Cover.” If appropriate, precede the credits with a sentence with a description of the cover (e.g., “The wind turbines on the cover are from the hills south of Tri-Cities Washington State.”).

Tables

Tables should be used when they are the most efficient and clearest way of presenting data to a reader, and they should supplement or support material presented in text and figures.

Table Titles: Every table must have a brief title describing what it is. The title should be typed using headline capitalization and should not have a period at the end. If the data in the table refer to a particular year or range of years, please give the year(s) after the title, preceded by a comma. If one unit of measure applies to the entire table, it may be presented at the end of the title, after the year (if given), and in parentheses. Material in parentheses should be set in sentence style (lowercase).

Table titles begin with the word Table followed by the table number (or, in books, by the chapter number, a hyphen, and the table number), then a period and space, then the title. Table titles should be placed above the tables.

Table Column Heads: If the entire column uses the same unit of measure, that unit can be included in the column head, within parentheses. Column heads should be typed with an initial capital letter only; they should be centered over columns and aligned on the bottom lines. Abbreviations are okay, but you must spell them out in the table notes unless the meaning is clear from the previous text.

Table Text: Columns containing words generally should be aligned left, but can be aligned center if preferred, or if the entries are two or fewer words (as long as the formatting is consistent within a given paper). Either title case or sentence case is acceptable for table text, but the choice for title or sentence case should be consistent throughout a given document or product. In a column consisting exclusively of information with the same sign (e.g., dollar amounts or percentages), the signs should be omitted from the cells and included in the column head. Columns with numbers usually appear centered beneath the column heads, but they may be aligned on the left, right, or the decimal points. Abbreviations are okay, but you must spell them out in the table notes.

Table Notes: Notes to a table should appear in this order below the table:

  1. Sources, which contain reference citations, which should follow Chicago’s author-date reference style, with full source information included as an entry in the reference list.
  2. Notes, which are explanations that apply to the table as a whole; they are preceded by Notes: in italic type, followed by a space.
  3. Footnotes, which are explanations that apply to particular entries in the table. They are identified with an italic, lowercase, superscript letter (this differentiates it from any notes that might appear elsewhere in the text and from superscript numbers that might be part of the table). The footnote appears in smaller type below the table.

Table References: Every table that appears must be referenced in the text, and tables must be numbered in the order in which they are mentioned. Use the word Table and the table number. Acceptable ways to refer to a table include the following:

Line Breaks and Hyphenation

In RFF style, words are not hyphenated from line to line; instead, the entire word should just go on the next line. Exceptions can be made for particularly awkward-looking lines, but it is preferable to rephrase sentences.

Word Choice and Usage

Abbreviations, Acronyms, and Initialisms

An abbreviation is a short form of a word or group of words, two types of which are initialisms and acronyms. With an initialism, the individual letters are pronounced (e.g., EPA, IPCC, and DOE). With an acronym, the resulting term is pronounced as a single word (e.g., NASDAQ, NASA). The following are general guidelines for abbreviations, acronyms, and initialisms created from proper names or multiple word phrases. Consult the RFF Specialized Word List for additional examples.

Identification: The first time a name or phrase appears, spell it out entirely, followed by the shortened form in parentheses. For example, The US Environmental Protection Agency (EPA) recently issued a report. A few exceptions to this exist (see US, UK, and UN below) but not many for proper names. Include the acronym only if the phrase appears at least three times in the text or if the acronym itself is more recognizable than the phrase.

Use of Periods: In general, use periods only after initials of people’s names but not in ones that are three letters or longer (R. S. Smith, JFK). There should be a space between initials when periods are used. Do not include periods in the following: PhD, MS, BS, and other degree types; US, USA, and other country acronyms; or DC, CA, and other state/region/jurisdiction acronyms.

Capitalization: In general, capitalize every letter of acronyms and initialisms, but do not capitalize every letter of a word or phrase that is not an acronym (including Politico). When in doubt, defer to Merriam-Webster.

If a phrase is being abbreviated, but it is not a proper noun, do not capitalize the spelled-out version, even if the abbreviation is in caps: gross national product (GNP), best-available technology (BAT). One prominent exception is Clean Development Mechanism (CDM) because this term is now commonly capitalized in all climate policy contexts.

State/Province Abbreviations: Write out the complete state/province name when it is used in text. In reference lists, tables, and other places where the abbreviation is appropriate, use US postal abbreviations (no periods).

EU, UK, UN, and US: Spell these names out when they are used as nouns; use the abbreviation as an adjective. They need not be spelled out on first use (though the meaning should be clear from the context). Do not use periods in the abbreviations. For example, Renewable energy in the United States not Renewable energy in the US; A UN special commission; The United Nations formed a special commission.

GDP and NASA: These acronyms are commonly known and understood by our audience; these need not be spelled out on first use.

Company Abbreviations: Spell out and capitalize the words Company and Corporation upon first mention of the company. Subsequently, these words can be dropped or abbreviated as Co. and Corp. The abbreviations Inc., Ltd., and LLP can usually be dropped in regular text and should always be omitted in reference listings.

Articles a or an before Abbreviations: Use a before abbreviations/acronyms that are pronounced with an initial consonant sound. Use an for initial vowel sounds: an EPA study, an FDA approval, a DOE report, a UN commission.

Legislation Designations: Use S. (Senate) and H.R. (House). Do include periods, and leave a single space between the S. or H.R. and the number.

Political Affiliations: For all elected officials whose political parties are publicly known, include the party and state abbreviations after the first mention of their name. For example, Senator Barack Obama (D-IL)

Compound Words

Compound words are formed when two separate words are used together to express a single concept. Compound words may pose spelling challenges because they can be open (with a space and no hyphen), hyphenated (with a hyphen), or closed (no space, no hyphen). Spelling of compound words does change with time (tending to move toward closed); the first authorities are the Chicago Manual of Style, Merriam-Webster, and the RFF Specialized Word List (see Appendix A). A few general guidelines as to RFF preferences appear below. See the Chicago Manual of Style hyphenation table for a comprehensive outline of hyphenation rules.

I need to log in to my account (to “log in” is a verb)
I need the
log-in credentials for my account (“log-in” is an adjective)
It was a successful log-in (a “log-in” is a noun)

I need to sign in to my account (to “sign in” is a verb)
I am signing in to my other account
 (to “sign in” is a verb)
I need the sign-in credentials for my account
 (“sign-in” is an adjective here)
Your sign-in has failed
 (“sign-in” is a noun here)

The regulation was rolled back (to “roll back” is a verb)
The regulation rollback was criticized
 (“rollback” is a noun here)

Latin Phrases

In general, avoid Latin phrases that have reasonable English substitutes, such as the following:

e.g. and i.e.: These abbreviations belong only in parenthetical clauses and should not be used in the main text. They are not italicized and must be followed by a comma. For example, Bones from a variety of small animals (e.g., a squirrel, a cat, a pigeon, and a muskrat) were found in the doctor’s cabinet. In the text, use for example or such as instead of e.g. and that is or in other words instead of i.e.

et al.: Et al. is an abbreviation for et alia. It is not italicized, is not preceded by a comma, and does not have a period after et but does have a period after al. Avoid using et al. in less technical documents; consider substituting and others or and their colleagues. For working papers and some other works, et al. is permissible. For use of et al. in text citations, see References: Author-Date System.

etc.: Avoid using etc.; use and so on or and others instead. (But these are unnecessary following e.g. or for example, which imply the existence of others.) Be sure the series carried on implicitly is self-evident from the context of the sentence.

ibid. / op. cit.: Since RFF calls for using the author-date reference system, ibid. and op. cit. should not be used, except in works written by legal scholars.

Some Latin phrases are acceptable, especially ones used frequently in economics or science, but should be used sparingly and only in publications that are intended for a technical audience. For publications with a wider array of audiences (e.g., reports, issue briefs, explainers, blog posts) these terms usually can be substituted with something simpler and more conversational, which doesn't require a less technical reader to look up the meaning. These include the following: ex post, ex ante, in vivo, ab initio. Note that these phrases should not be italicized in the final text.

Word Choice

a / an: Use a before words that start with a consonant sound and an before words (and abbreviations and acronyms) that start with a vowel sound.

above / below vs. specific cross-references: Use earlier and later to indicate a general, inclusive direction for whatever is being cross-referenced. Use more precise phrases to direct the reader’s attention to a specific discussion. Examples include the following:

a number of: Avoid this vague phrase, which doesn’t give an indication of what number between one and a gazillion. Substitute something more meaningful: for example, one or two, a few, several, some, many, most of, nearly all of, thousands, hundreds. Better yet, specify exactly what number.

author vs. I / we: In nearly all instances, the use of the first person (I and we) not only is acceptable, but is preferable to the ponderous third person (for example, rather than The authors evaluated 24 different pollution control programs … use We evaluated …) and the indirect (for example, rather than This paper considers, first, the relevance of … use this substitute: In this paper, we consider, first …).

Note, however, that use of the third person and indirect references is permissible for working papers and elsewhere at the authors’ discretion.

because / since: Both mean for the reason that. Because is the stronger and plainer word and should be used unless the passage of time is involved; in that case, since would be appropriate.

biannual / biennial: A biannual event takes place twice a year; a biennial one takes place every two years.

data: Strictly speaking, data is the plural of datum, which is a piece of information; therefore, strictly speaking and traditionally, data takes a plural verb (The data are conclusive). However, increasingly, data is used as a collective noun with a singular verb (Our data is substantially the same as theirs). Either is acceptable in RFF publications, as long as it is consistent within a given document.

economic / economics: Economic research is preferable over economics research, for the sake of consistency. However, note that your choice may depend on the context: economics is a noun and economic is an adjective, so economic research places more emphasis on the word research, with economic as a modifier, whereas economics research places relatively more emphasis on economics.

ensure / assure / insure: While all three mean to make sure, they have slightly different usage. Ensure simply means to make sure and is the preferred word unless one of the others is called for. Assure means to put at ease or make comfortable. Insure means to make sure via a guarantee and involves money.

forgo / forego: Use forgo for do without or lack (forgone benefits). Use forego for going before (a foregone conclusion).

paper / chapter / article: Use in this paper, in this chapter, or in this article rather than here or below. Papers being published in journals are articles and in books are chapters.

people / persons: Use people for groups of human beings, especially when the groups are larger, uncounted, or of indefinite number. Use persons for smaller, countable groups (Six persons answered the question in the affirmative). Because people is always correct, when in doubt, you can always use people instead of persons.

presently: This word is ambiguous, as it can mean either soon or now. Use a clearer word to avoid the possibility of confusion.

that / which: Both words are used to introduce clauses in a sentence, and the distinction has to do with whether the clause is restrictive and necessary to the meaning of the sentence or nonrestrictive and descriptive but not necessary to the meaning of the sentence. For example:

Descriptive (nonrestrictive) clauses are set off with commas; restrictive clauses are not. One useful test: if removing the clause doesn’t change the meaning of the sentence, use commas and which. When removing the clause changes the sentence’s meaning, use that without commas.

there is / there are: Often, these two words are used to introduce an indirect statement that could be made direct: for example, There are many people who wish they could fly. Stronger, more authoritative writing eliminates the there is/are in favor of making the rest of the sentence a direct statement: Many people wish they could fly.

use / utilize: While utilize does have a meaning that is more specific than use (that is, something employed in a new or practical way), utilize is often simply an inflated way of saying use. Unless you definitely mean utilize, use use.

we: We can be used variously to mean we, the coauthors; we, the folks at RFF; we, the folks at [some other organization or corporation]; we, the people of the United States; we, people in general; or we, the entire human race. Any of these uses are acceptable, providing it is clear from the context which precisely is meant and multiple uses are not combined in a single paragraph.

whether / if: Both words introduce conditions. Use whether when alternatives are being provided. If may be used when one possibility is being raised (although whether can be appropriate in that case as well).

whether / whether or not: In most cases, the or not can and should be left out.

while / whereas / though / although: All these words relate clauses to the main part of the sentence. While, which technically indicates a time correlation (Nero fiddled while Rome burned), may substitute for although or whereas, especially if a conversational tone is desired (While many readers may disagree, the scientific community has overwhelmingly adopted the conclusions here presented), as long as it does not introduce ambiguity. Whereas indicates something contrary (Nero fiddled, whereas Terpsichore danced). Though and although can be used interchangeably to mean however, despite the fact that, or even if.

Gender-Neutral Language

Opt for gender-neutral language whenever possible. For example, use humankind rather than mankind, people rather than men and women, they rather than he or she to refer to an individual of unspecified gender, esteemed guests rather than ladies and gentlemen.

References: Author-Date System

RFF uses the author-date system for referencing scholarly sources in its publications. Please note that including the year at the start of the reference is favored by the RFF style guide, though the suggested format differs in the Chicago Manual. The author-date system consists of two main elements: the reference list and the text citation. This section contains a brief set of guidelines for preparing a reference list and creating text citations. Examples of common types of references and text citations appear in the Table of Reference Samples. More detailed information—and guidelines for citing sources not included here—may be found in chapters 14 and 15 of the Chicago Manual of Style, noting again that judgment should be applied if any discrepancies are observed.

RFF style and Chicago style differ somewhat for references:  (1) RFF does not use quotation marks around any titles in the reference listings (although titles of articles in periodicals, chapters in books, or working papers, as well as any other titles not in italics, should be in quotes where mentioned in the text); and (2) RFF uses et al. for works with more than two authors instead of three (a variation that the “Text citations of works with more than three authors” section of the Chicago Manual says is used “in some science publications”).

Reference List: The reference list is a type of bibliography. It contains the full bibliographic citation for each source referred to in the main text of a book, chapter, article, or discussion paper. In articles and discussion papers, the reference list appears after all text and appendixes. In books, the reference list appears at the end of a chapter (if the book has multiple contributors) or at the end of the book (in single-author books). The reference list should be differentiated from Selected Readings, Suggested Readings, or other types of bibliographies, which may include sources not cited within the main text.

Text Citations: A text citation is a shorthand for each reference and appears within the main text. The text citation provides enough (and only enough) information for a reader to locate a source in the reference list. In most cases, the text citation consists of the last name of the author plus the year of publication.

Preparing a Reference List

Two overall guidelines are important to remember when preparing or copyediting a reference list.

First, when in doubt, authors should provide too much information rather than too little. The RFF copyeditor will eliminate or rearrange information to conform to general reference style. If information is missing, however, the copyeditor will have to query the author.

Second, be as consistent as possible about formatting and punctuation. The Chicago Manual of Style and RFF accept some variations in styling references in a reference list, as long as the variations are consistent throughout a document.

References to Books

Each reference to a book must contain the following:

References to Periodicals

Information for references to articles in periodicals (including journals and magazines) can usually be found on the title page of the periodical and the first page of the article. Each reference to an article in a periodical must contain the following:

Assembling the Reference List

Preparing Text Citations

Elements of a Text Citation

Text citations in the author-date reference system consist of a very brief reference to the author(s) (or editor or institution) and the year of publication, with no intervening comma. Where material is quoted from another source, the page number(s) should also be cited.

Author: The reference to the author is usually the surname(s) or word(s) by which a source was alphabetized on the reference list.

Year of publication: The year used in the text citation should match the year that follows the author name in the reference list. Add lowercase letters after the year to distinguish items with the same author(s) and date in the reference list. These should be listed alphabetically by title, with the one coming first alphabetically designated as a and so forth. Forthcoming should be used in place of a date for books or articles accepted for publication. In a reference listing, it is capped and appears where the date would: Taylor, K. Forthcoming. In a text citation, it is lowercase and preceded by a comma: (Taylor, forthcoming).

Page numbers: Page numbers should be included in text citations where material is quoted from another source (unless the source is unpaginated); they are generally not necessary otherwise, unless an author wishes to refer readers to specific material within a source. If page numbers are included, they are separated from the year by a comma and space. Do not use p. or pp.

Determining the Correct Text Citation

Text citations usually appear in the text enclosed within parentheses, with no punctuation between the author and year. They also may be incorporated in the text (see the next section). Variations include the following:

One work by one author

(Toman 1990)

One work by one author, with page citation

(Toman 1990, 366)

More than one work by one author

(Krupnick 1990, 1992a, 1992b, 1999)

More than one work by one author, with page citations

(Kopp 1996, 234; 2000, 567–78)

More than one work (the order is at the discretion of the author, though alphabetical or chronological is suggested)

(Toman 1990; Krupnick 1992b; Kopp 1996)

Incorporating the Text Citation into the Text

The text citation should be placed in the text where it makes sense. Where the citation is not an integral part of the sentence, it should appear in parentheses.

Sometimes the author of the referenced work has a role in the sentence. In this case, the name should not be repeated twice, and only the year should be added in parentheses. (Note that et al. is used in the text citation, while and colleagues is used in regular text.)

Other times the text citation representing the referenced work has a role as a noun in the sentence. In such cases, the parentheses appear only around the year.

Verb tense when discussing research: It is generally best to use the present tense when discussing literature or the results of research. Past tense verbs may be appropriate, however, when discussing the activities of researchers: for example, Jenkins and colleagues (2019) conducted the interviews.

Table of Reference Samples

The table below shows how different types of sources appear in the reference list and in the text citation. Follow these samples for punctuation, capitalization, and use of italics.

Type of Source

Reference List

Text Citation

Books or reports with one author or editor

A URL may be included for reports but is not required. Include the report number if possible.

Nordhaus, William D. 1994. Managing the Global Commons: The Economics of Climate Change. Cambridge, MA: MIT Press.

(Nordhaus 1994)

O’Shaughnessy, Eric, Jenny Heeter, Jeff Cook, and Christina Volpi. 2017. Status and Trends in the U.S. Voluntary Green Power Market (2016 Data). Technical Report NREL/TP-6A20-70174. Golden, CO: National Renewable Energy Laboratory. https://www.nrel.gov/docs/fy18osti/70174.pdf.

Books or reports with two authors or editors

Portney, Paul R., and John P. Weyant, eds. 1999. Discounting and Intergenerational Equity. Washington, DC: Resources for the Future.

(Portney and Weyant 1999)

Books or reports with three or more authors or editors

Russell, Clifford S., Winston Harrington, and William J. Vaughan. 1986. Enforcing Pollution Laws. Washington, DC: Resources for the Future.

(Russell et al. 1986)

Books or reports with an organization or agency as author

Note placement of report numbers and originating agency office.

Also note that an agency name should appear as an abbreviation or acronym when possible, followed by the complete name in parentheses on the reference list.

EPA (US Environmental Protection Agency). 1995. Oral History Interview-4, William K. Reilly. EPA 202-K-95-002. Washington, DC: EPA.

(EPA 1995)

———. 1986a. Air Quality Criteria Document for Lead. 4 vols. and addendum. Environmental Criteria and Assessment Office, Office of Research and Development. Research Triangle Park, NC: EPA.

(EPA 1986a)

———. 1986b. Regulatory Impact Analysis: Protection of Stratospheric Ozone. Stratospheric Protection Program, Office of Program Development, Office of Air and Radiation. Washington, DC: EPA.

(EPA 1986b)

IPCC (Intergovernmental Panel on Climate Change). 1990. Climate Change: The IPCC Scientific Assessment. Edited by J. T. Houghton, G. J. Jenkins, and J. J. Ephraums. New York: Cambridge University Press.

(IPCC 1990)

Type of Source

Reference List

Text Citation

Chapters in a book, including volume editors and page span

Parson, E. A. 1993. Protecting the Ozone Layer. In Institutions for the Earth: Sources of Effective International Environmental Protection, edited by P. M. Haas, R. O. Keohane, and M. A. Levy, 340–62. Cambridge, MA: MIT Press.

(Parson 1993)

Workshop or conference papers or PowerPoint presentations

Hammitt, J. K. 1986. The Timing of Regulations to Prevent Stratospheric-Ozone Depletion. Paper presented at United Nations Environment Programme (UNEP) Workshop on the Control of Chlorofluorocarbons, Leesburg, VA, September 1986.

(Hammitt 1986)

Discussion or working papers


No.” may or may not be included, depending on the source.

Burtraw, Dallas. 1995. Cost Savings Sans Allowance Trades? Evaluating the SO2 Emission Trading Program to Date. Discussion Paper 95-30-REV. Washington, DC: Resources for the Future.

(Burtraw 1995)

Muehlegger, E., and D. S. Rapson. 2018. Subsidizing Mass Adoption of Electric Vehicles: Quasi-Experimental Evidence from California. NBER Working Paper No. 25359. Cambridge, MA: National Bureau of Economic Research.

Manuscripts in review

Peter Christensen, Ignacio Sarmiento-Barbieri, and Christopher Timmins. Housing Discrimination and the Pollution Exposure Gap in the United States. (Manuscript in review.)

(Christensen et al., in review)

Newspaper articles, without byline

Washington Post. 1995. Dan Morgan’s Republicans Defect to Kill Curbs on EPA. July 29, A1, A9.

(Washington Post 1995)

Newspaper articles, with byline

Cushman Jr., John H. 1997. Virginia Seen as Undercutting US Environmental Rules. New York Times, January 19, A22.

(Cushman 1997)

Periodicals with volume, page, and doi numbers

Adams, R. M. , K. J. Bryant, B. A. Mccarl, D. M. Legler, J. O’Brien, A. Solow, and R. Weiher. 1995. Value of Improved Long-Range Weather Information.” Contemporary Economic Policy 13:10–19. https://doi.org/10.1111/j.1465-7287.1995.tb00720.x.

(Adams et al. 1995)

Periodicals with volume, issue, and page numbers

Bradford, David F. 1975. Constraints on Government Investment Opportunities and the Choice of Discount Rate. American Economic Review 65 (50): 887–99.

(Bradford 1975)

Periodicals with volume, month or season, and page numbers

Manne, A. S. 1994. The Rate of Time Preference: Implications for the Greenhouse Debate. Journal of Economic Perspectives 8 (Fall): 3–17.

(Manne 1994)

Type of Source

Reference List

Text Citation

Memoranda

Jones, Anne. 1992. Memorandum from Anne Jones, senior economist, Eastern Research Group, Lexington, MA, to Susan Burris, EPA. September 25.

(Jones 1992)

Correspondence or personal communication

None

(Julie Cantor, pers. comm., June 20, 2020)

(Jonathan Lee, Facebook direct message to author, May 5, 2017)

Articles from Federal Register

EPA (US Environmental Protection Agency). 1979. Advanced Notice of Proposed Rulemaking. Federal Register 44: 60056, October 17.

(EPA 1979)

Online references

These must include the full URL and the date of publication or revision (preferable) or, lacking that, the date last accessed by the author(s).

For sources that include a date of publication or revision, use the year of publication in the reference list entry and text citation.

Harnack, Andrew, and Gene Kleppinger. n.d. Documenting Electronic Sources on the Internet. Accessed November 25, 1998. http://falcon.eku.edu/honors/beyond-mla.

(Harnack and Kleppinger, n.d.)

EPA (US Environmental Protection Agency). 2020. Environmental Measurements and Modeling. Last updated January 24, 2020. https://www.epa.gov/measurements-modeling.

(EPA 2020)

Appendix A: Lists and Tables

RFF Specialized Word List

A

acknowledgment (not acknowledgement)

act; the act; Clean Air Act

administration (n), not Administration (as in Clinton administration)

adviser (not advisor)

air pollution (n, adj)

air quality (n), air-quality (adj)

American (n), for citizens of the United States. As an adjective, use US instead.

among (not amongst)

analytical (not analytic)

anti- prefix. Usually close up the word, unless it would create a double letter: antidemocratic; anti-intellectual; see the Chicago Manual of Style hyphenation table.

appendix, appendixes (plural)

B

Btu (British thermal unit), Btus buildup (no hyphen)

business-as-usual (BAU) (adj.)

by-product

C

CAFE: corporate average fuel economy

cap-and-trade (adj), cap and trade (n), not cap & trade

chair, as in chair of the board of directors not chairman or chairwoman

Clean Air Act; the act

Clean Development Mechanism (CDM)

clean energy standard. Capitalize the acronym (CES), and do not capitalize the phrase (Clean Energy Standard).

cleanup not clean-up (n, adj), clean up (v)

climate change (n, adj) no hyphen

Co., Corp., and Inc. See Abbreviations, Acronyms, and Initialisms section in this style guide.

command-and-control (CAC) (adj)

coauthor, not co-author or co author

co-chair, not cochair

cofounder, not co-founder

Conference of Parties (COP); COP-1, first conference of the parties to the FCCC

congressional, not Congressional (adj). Also: 103rd Congress, not 103d.

contingent valuation (n, adj)

cost-effective (adj), cost-effectiveness (n)

cost-efficient (adj), cost efficiency (n, adj)

cost-saving (adj), cost savings (n)

criteria air pollutants

cutoff (adj, n), cut off (v)

D

database, data set (n)

decisionmaker, decisionmaking

Democrat versus democrat. Capitalize when it refers to the US political party.

E

EIEE should be RFF-CMCC European Institute on Economics and the Environment (EIEE) on first use, then EIEE thereafter in the document; do not replace the and with an ampersand (&).

electric grid (not electrical grid nor electricity grid; both are generally acceptable, but RFF style prefers the former)

electricity bill (not electric bill)

email (Email at beginning of sentences) no hyphen

emissions versus emission. Use the plural form as an adjective: emissions reduction(s), emissions-permit trading (note the hyphen in the compound modifier).

endpoint (n, adj)

energy efficiency (n, adj), energy-efficient (adj preceding noun), energy efficient (adj after noun). For example, The energy efficiency standards improve energy efficiency and require energy-efficient light bulbs to be installed instead of those that are not energy efficient.

environmental impact statement (EIS)

European Union (n), EU (adj.) Note that the acronym need not be spelled out on first use (though the meaning should be clear from the context).

Exxon Valdez (ship name is italicized, but owner is not: USS Enterprise)

F

federal (not Federal)

feedstock (not feed-stock)

follow-up (n, adj), follow up (v)

forgo versus forego. Use forgo for do without or lack; use forego for going before. Examples: forgone benefit, foregone conclusion

free rider, free riding (n), free-riding (adj)

fresh water (n), freshwater (adj)

G

geographic (adj) (not geographical)

geographic information systems (GIS)

geologic (adj) (not geological)

Global Climate Policy Partnership (GCPP). Note that we use the article the alongside the acronym as in the GCPP.

greenhouse gas (GHG) (n, adj), greenhouse gases (GHGs)

gross domestic product (GDP). Note that the acronym need not be spelled out on first use (though the meaning should be clear from the context). If GDP and GNP are defined in close proximity in the same publication, spell out both GDP and GNP.

gross national product (GNP)

groundwater

H

hazardous air pollutants (HAPs)

health care (n), health-care (adj)

high-, higher-, highest-[risk/cost/etc.] (adj)

his/her, his or her: replace with their

Hotelling’s Rule, Hotelling rents

humankind (not mankind)

human-made (not manmade)

hydro (short for hydropower). The use of hydro alone is acceptable in informal writing, but spelling out hydropower or hydroelectric power is preferred.

I

Inc. See Abbreviations, Acronyms, and Initialisms section in this style guide.

index. Plural is indexes when it refers to the lists in a book but indices when it refers to a number or mathematical expression (for example, population indices).

Indian (n, adj) refers to the people and country of India. For indigenous people of the Americas, use Native American or the specific tribe name.

instream

internet

irreversibility/ies

J

joint implementation (JI)

judgment (judgement is British spelling and acceptable for works written and published for a primarily European audience)

K

Kazakhstan (not Kazakstan)

L

land use (n), land use (adj) (affects land use, land use change)

learning by doing (LBD) (n), learning-by-doing (adj)

least cost (n), least-cost (adj) (at least cost, least-cost solution)

long-standing

low-, lower-, lowest- (adj) (low-risk investment, lower-risk investment, lowest-risk investment)

locally undesirable land uses (LULUs)

M

mankind: do not use. Substitute gender-neutral language, such as humankind.

manmade: do not use. Substitute synthetic, human-made, anthropogenic, or artificial.

marketplace (n, adj)

mid- prefix: mid-1985, mid-nineteenth century, midrange, midlatitude; see the Chicago Manual of Style hyphenation table.

model year (MY)  Used for vehicles; e.g., MY 2015 

municipal solid waste (MSW)

N

NASA. Note that it’s not necessary to spell this out on first use (though the meaning should be clear from the context).

National Forest System, National Park System, national forests, national parks

net zero (n), net-zero (adj) (Climate activists are eager for carbon emissions to reach net zero, net-zero emissions)

the Netherlands

New England

non- prefix: Usually close up the word, without a hyphen: nonagency, nonpoint, nontechnical. Except: non-OECD, non-US, non-oil (adj); see the Chicago Manual of Style hyphenation table.

nongovernmental organizations (NGOs)

nonpoint source(s) (n), nonpoint-source (adj)

notice of proposed rulemaking (NPRM)

O

offstream

online, offline

Oriental: do not use. Substitute Asian or Middle Eastern or a specific nation.

P

Pareto coefficient

payoff (n, adj), pay off (v)

phaseout (n), phase out (v)

Pigouvian

policymaker (n), policymaking (n, adj)

priority setting (n), priority-setting (adj)

protocol: Montreal Protocol, Kyoto Protocol, the protocol

Q R

research and development (R&D)

real world (n), real-world (adj)

re-create (to create again) versus recreate (to take recreation); re-form (to form again) versus reform (to change for the better)

renewable energy resources, renewables. Use the complete phrase for the first instance.

renewable portfolio standard. Capitalize the acronym (RPS), and do not capitalize the phrase (Renewable Performance Standard).

Republican versus republican. Capitalize when it refers to the US political party.

rulemaking (adj, n)

runoff (n, adj), run off (v)

S

salt water (n), saltwater (adj)

sea level rise (no hyphen). Avoid using the acronym SLR.

set-asides (n), set aside (v)

slowdown (n), slow down (v)

snowmelt

socioeconomics (n), socioeconomic (adj)

state:  see Geographic Regions and Descriptors section

start-up (n, adj), start up (v)

state implementation plan (SIP) or plans (SIPs)

sulfur (not sulphur)

supply and demand (n), supply-and-demand (adj)

surface water (n, adj)

T

they/their:  can be used as singular to be gender-neutral; use instead of he or she, he/she, his/her, or his or her

Third World: do not use. Substitute developing world/countries/nations.

toward (not towards)

toxic substance(s), toxic(s). Use the complete phrase for the first instance.

tradable (not tradeable)

trade-off (n, adj), trade off (v)

transaction costs

U

UK (adj only); spell out as United Kingdom if used as a noun. Note that the acronym need not be spelled out on first use (though the meaning should be clear from the context).

UN (adj only); spell out as United Nations if used as noun. Note that the acronym need not be spelled out on first use (though the meaning should be clear from the context).

undersecretary (n, adj)

US (adj only); spell out as United States if used as a noun. Note that the acronym need not be spelled out on first use (though the meaning should be clear from the context).

United Nations Framework Convention on Climate Change (UNFCCC) (include full name on first reference)

V

value of a statistical life (VSL); this is RFF’s preferred version of the phrase, for the sake of consistency

WXYZ

web (n, adj), webmaster, webpage, website

well-being

wide- suffix: see the Chicago Manual of Style hyphenation table

willingness to accept (n), willingness-to-accept (adj)

willingness to pay (n), willingness-to-pay (adj) (WTP)

zero-emissions vehicle (not zero-emission vehicle). Note that the ZEV program is a unique case, because most official sources do not hyphenate the phrase and omit the “s” in “Emission”: Zero Emission Vehicle program.

Units of Measure

Metric unit

English unit        

meter, m

foot, ft

kilometer, km

mile, mi

centimeter, cm

inch, in

hectare, ha

acre

kilogram, kg

pound, lb

liter, L

quart, qt; gallon, gal

metric ton (better than tonne)

ton

degrees Celsius, °C        

degrees Fahrenheit, °F        

Additional help with units of measure can be found in the Chicago Manual of Style (especially the “International System of Units” and “US Measure” sections). The following units appear frequently in RFF publications.

Currency Abbreviations

Primary Country/Countries of Use

Currency Name

Currency Symbol

United States

Dollar

$, US$

Australia

Australian dollar

$, A$, AU$

Canada

Canadian dollar

$, C$

Switzerland

Swiss franc

Fr, SFr, FS

Japan

Japanese yen

¥

New Zealand

New Zealand dollar

$, NZ$

Many European countries

Euro

United Kingdom

Pound sterling

£

Sweden

Swedish krona

kr

Denmark

Danish krone

kr

Norway

Norwegian krone

kr

Singapore

Singapore dollar

$, S$

Czech Republic

Czech koruna

Hong Kong

Hong Kong dollar

$, HK$

Mexico

Mexican peso

$, Mex$

Poland

Zloty

Russia

Ruble

Turkey

Turkish lira

South Africa

Rand

R

Mainland China

Yuan

Chemical Compounds

carbon dioxide (CO2)

carbon monoxide (CO)

carbon tetrachloride

chlorofluorocarbons (CFCs)

DDT (dichlorodiphenyltrichloroethane; use of abbreviation is sufficient)

dioxin

ethylene dibromide

hydrocarbons (HCs)

hydrofluorocarbons (HFCs)

methane (CH4)

nitrogen dioxide (NO2)

nitrogen oxide(s) (NOx). Note italic, lowercase, subscript “x,” because the “x” is a variable that could be a 2, 3, or 4; “Ox” is not an abbreviation for “oxide.”

ozone (O3)

particulate matter (PM); PM2.5, PM10 (particulate matter 2.5/10 micrometers or smaller in diameter). Note: when subscript is not available, use PM2.5 or PM10.

polychlorinated biphenyls (PCBs)

sulfur dioxide (SO2)

total suspended particulates (TSP)

volatile organic compounds (VOCs)

Agencies and Organizations

US Government Agencies

The following list is neither comprehensive nor exhaustive but includes many of the agencies that come up frequently in RFF publications.

Atomic Energy Commission (AEC)

Bureau of Economic Analysis (BEA; part of Department of Commerce)

Bureau of Land Management (BLM)

Centers for Disease Control and Prevention (CDC)

Consumer Product Safety Commission (CPSC)

Energy Information Administration (EIA; part of DOE)

Federal Communications Commission (FCC)

Federal Deposit Insurance Corporation (FDIC)

Federal Energy Regulatory Commission (FERC)

Federal Housing Finance Agency (FHFA)  

Federal Maritime Commission (FMC)

Federal Power Commission (FPC)  

Federal Radiation Council (FRC)  

Federal Reserve Board (FRB)  

Federal Trade Commission (FTC)  

Forest Service. See USDA Forest Service

Interstate Commerce Commission (ICC)

Mining Safety and Health Administration (MSHA)  

National Aeronautics and Space Administration (NASA)  

National Highway Traffic Safety Administration (NHTSA)  

National Oceanic and Atmospheric Administration (NOAA)  

National Park Service (NPS)

National Renewable Energy Laboratory (NREL)  

National Transportation Safety Board (NTSB)  

Nuclear Regulatory Commission (NRC)

Occupational Safety and Health Administration (OSHA)  

Office of Management and Budget (OMB)

President’s Council of Economic Advisers (CEA)

Science Advisory Board (SAB)

Securities and Exchange Commission (SEC)  

USDA Forest Service

US Department of Agriculture (USDA)

US Department of Commerce (DOC)  

US Department of Defense (DOD)  

US Department of Energy (DOE). Refer to it subsequently as “DOE,” not “the DOE” or “US DOE.”

US Department of Health and Human Services (HHS)  

US Department of the Interior (DOI)

US Department of Labor (DOL)  

US Department of Justice (DOJ)

US Department of Transportation (DOT)

US Environmental Protection Agency (EPA). Include US when spelling out in full on first mention to distinguish from state EPAs. Refer to it subsequently as “EPA,” not “the EPA” or “US EPA,” and as “the agency,” not “the Agency.”

US Fish and Wildlife Service (FWS)

US Food and Drug Administration (FDA)

US Government Accountability Office (GAO)  

US Geological Survey (USGS)

Other Agencies and Organizations

The following list is neither comprehensive nor exhaustive but includes many of the agencies and organizations that come up frequently in RFF publications.

American Chemistry Council (ACC)

American Forest and Paper Association (AF&PA)

American Iron and Steel Institute (AISI)

American Petroleum Institute (API)

American Water Works Association (AWWA)

Audubon Society

Consultative Group on International Agriculture Research (CGIAR)

Energy Modeling Forum (EMF)

Environmental Defense Fund (EDF)

Greenpeace

Intergovernmental Panel on Climate Change (IPCC)

International Energy Agency (IEA)

International Monetary Fund (IMF)

International Standards Organization (ISO)

National Academy of Sciences (NAS)

National Association for the Advancement of Colored People (NAACP)

National Center for Environmental Assessment (NCEA)

National Center for Environmental Research (NCER)

National Exposure Research Laboratory (NERL)

National Institute of Environmental Health Sciences (NIEHS)

National Institute of Occupational Safety and Health (NIOSH)

National Renewable Energy Laboratory (NREL)

National Research Council (NRC)

National Science Foundation (NSF)

National Wildlife Federation (NWF)

Natural Resources Defense Council (NRDC)

Organisation for Economic Co-operation and Development (OECD)

[State Name] Public Utility/ies Commission (identify which state)

Public Interest Research Group (PIRG)

Resources for the Future (RFF) (For any article we publish, spell out the full name Resources for the Future when it appears for the first time, followed by (RFF), and then use simply RFF throughout the publication thereafter)

UN Food and Agriculture Organization (FAO)

United Nations Conference on Environment and Development (UNCED; 1992, Rio de Janeiro)

World Health Organization (WHO)

World Meteorological Organization (WMO)

World Wildlife Fund (WWF) for US and Canadian offices; World Wide Fund for Nature (WWF) for international

World Trade Organization (WTO)

Laws, Legislation, and Treaties

The following list is not comprehensive or exhaustive but includes many of the US environmental laws that may appear in RFF publications. Dates of enactment are included here in parentheses and can be included in text as preferred by the author. (Note that for consistency, RFF includes the serial/Oxford comma in the names of legislation, regardless of GPO style.)

Air Quality Act (1967)

Administrative Procedures Act (APA)

Comprehensive Electricity Competition Act (CECA)

Clean Air Act (CAA) (1963; amended in 1970)

Clean Air Act Amendments of 1990 (1990 Amendments, the CAA amendments, the amendments)

Clean Water Act (CWA) (1977)

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (1980)

Delaney Clause (part of Federal Food, Drug, and Cosmetic Act)

Emergency Planning and Community Right-to-Know Act (EPCRA) (1986)

Energy Act of 2020

Energy Policy and Conservation Act (EPCA) (1975)

Endangered Species Act (ESA)

Federal Food, Drug, and Cosmetic Act (FFDCA) (1958)

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) (1947)

Federal Water Pollution Control Act (1948; amended in 1972 to become the Clean Water Act)

Food Quality Protection Act (1996)

General Agreement on Tariffs and Trade (GATT) (1947)

Hazardous and Solid Waste Amendments (to RCRA) (1984)

Mercury Containing and Rechargeable Battery Management Act (1996)

Mineral Leasing Act (1920)

Mining Law (1872)

Multiple Use Sustained Yield Act (1960)

National Ambient Air Quality Standards (NAAQS) (Note: NAAQS is a plural; if it is necessary to refer to a single standard, write “one of the NAAQS” or “one of the standards” after introducing the proper name in full.)

National Environmental Policy Act (NEPA)

National Forest Management Act (NFMA) (1976)

National Priorities List (NPL)

National Trails Act

National Wildlife Refuge System Improvement Act (1997)

North American Free Trade Agreement (NAFTA)

Public Utility Regulatory Policies Act (PURPA) (1978)

Resource Conservation and Recovery Act (RCRA) (1976)

Resources Planning Act (RPA)

Safe Drinking Water Act (SDWA) (1974)

Solid Waste Disposal Act (SWDA) (1995)

Superfund (1980; an amendment to the Comprehensive Environmental Response, Compensation, and Liability Act)

Superfund Amendments and Reauthorization Act (SARA) (1986)

Surface Mining Control and Reclamation Act

Toxic Substances Control Act (TSCA) (1976)

Toxics Release Inventory (TRI) (1986)

Water Pollution Control Act (1948)

Water Quality Acts (1965, 1987)

Wild and Scenic Rivers Act (1968)

Wilderness Act (1964)

Appendix B: Editing Guidelines for Freelancers

Quick Listicle: A “Cheat Sheet” of the Most Important Takeaways from the Chicago Manual of Style

Capitalization: Rules for capitalization follow the Chicago Manual of Style.

Percentages: In text, use numerals and spell out the word percent: 10 percent. (Note: Exceptions may be made for discussion papers, which can often be fairly technical. The percent sign may be used throughout the text, but a mix of the two usages is not permitted.)

Use the noun form, percentage, when referring to the numerical value (i.e., when a number is not given). For example, The percentage of Americans who live in poverty increased this year.

EU, UK, UN, and US: Spell these names out when they are used as nouns; use the abbreviation as an adjective. They need not be spelled out on first use (though the meaning should be clear from the context). Do not use periods in the abbreviations. For example, Renewable energy in the United States not Renewable energy in the US; A UN special commission; The United Nations formed a special commission.

RFF-CMCC European Institute on Economics and the Environment (EIEE): Spell out and include the acronym in parentheses on first use; use acronym (EIEE) thereafter in the document. Do not replace the and with an ampersand (&).

GDP and NASA: These acronyms are commonly known and understood by our audience; these need not be spelled out on first use.

US Environmental Protection Agency (EPA): Include US when spelling out in full on first mention to distinguish from state EPAs. Refer to it subsequently as EPA, not the EPA or US EPA, and as the agency, not the Agency.

Gender-Neutral Language: Opt for gender-neutral language whenever possible. For example, use humankind rather than mankind, human-made rather than man-made, people rather than men and women, they rather than he or she to refer to an individual of unspecified gender, esteemed guests rather than ladies and gentlemen.    

Centuries: Spell out ordinal names of centuries: nineteenth century, twentieth century.

Money and Currency: For 1988 dollars, use 1988$ or dollar year 1988 and not $1988. When it is necessary to specify both the dollar year and the currency’s country, put a space between the dollar year and the currency: 2000 US$. For example, The current tax is $3.40 (2000 US$) per gallon. For dollar amounts where you need to specify US dollars, use US$5,000.

Quotation Marks: When it comes to putting periods and commas inside or outside quotation marks, RFF uses American (or aesthetic) style—that is, periods and commas go inside quotation marks, except in rare instances when doing so could lead to confusion or misunderstanding. Colons and semicolons go outside the quotation mark. Question marks and exclamation points follow logical style and go inside or outside, depending on whether they are part of the quotation.

Company Abbreviations: Spell out and capitalize the words Company and Corporation upon first mention of the company. Subsequently, these words can be dropped or abbreviated as Co. and Corp. The abbreviations Inc., Ltd., and LLP can usually be dropped in regular text and should always be omitted in reference listings.

Compound Words: Generally, close up compounds rather than use a hyphen: policymaker, taxpayer, stakeholder, decisionmaker. (Well-being is an exception.)

Additional Specialized Words: electric grid not electrical grid, and emissions not emission.

c