GiveWell's CEA of insecticide-treated net (ITN) distributions (public)

	A	C	E	F
1	Guide to interpreting this cost-effectiveness analysis

2	Sheet descriptions
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4			Main CEA	This sheet contains the primary calculations that result in final cost-effectiveness estimates. This sheet draws on inputs from the "Inputs" sheet and inputs calculated in the other supplemental sheets listed below.
5			Effective coverage	This sheet contains our calculations of how much protection nets distributed in grantee programs provide compared to the protection provided by nets distributed in the trials that inform our treatment effect estimates.
6			Counterfactual malaria	This sheet contains our calculations of how high malaria mortality and prevalence rates would be in the absence of net distributions.
7			Insecticide resistance	This sheet contains our calculations of how much the protective effect of nets is reduced by insecticide resistance among malaria-transmitting mosquitos.
8			Leverage/Funging	This sheet contains our calculations of the impact that crowding in and crowding out funding by other contributors has on the benefits of the program.
9			Inputs	This sheet contains all of the manually entered input values informing the CEA, along with the sources and reasoning supporting them. This sheet also contains inputs sourced from the "GBD estimates" sheet.
10			Net decay model	This sheet contains our models of physical net decay over time, which inform calculations on the "Effective coverage" sheet.
11			GBD estimates	This sheet contains disease burden and population datasets downloaded from the Institute of Health Metrics (IHME)'s Global Burden of Disease (GBD) project.
12			Simple CEA	This sheet contains a simplified version of the CEA that is designed to be comparable to our CEAs of other programs.
13			Confidence intervals	This sheet contains our best guesses of the 25th and 75th percentile values for each of the parameters of our simple CEA.
14			Sensitivity analysis	This sheet contains the outputs of our sensitivity analysis that tests the cost-effectiveness ranges that would result from updating certain inputs to their 25th or 75th percentile values.
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16	Terminology key
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18		Terms specific to this CEA
19			ITN	Insecticide-treated nets (ITNs) are mosquito nets have have been treated with insecticidal chemicals designed to kill and/or repel mosquitoes. ITNs are an umbrella category of nets that include conventionally treated nets (CTNs), long-lasting insecticide-treated nets (LLINs), and newer types of nets like PBO and chlorfenapyr nets.
20			LLIN	Long-lasting insecticide-treated nets (LLINs) are mosquito nets that have been treated with insecticides using a method that extends the effectiveness of the insecticide for multiple years without retreatment. Some of the nets (which we sometimes refer to as "standard nets") distributed in programs we consider funding are LLINs.
21			Pyrethroid	A class of insecticides commonly used to treat LLINs. The pyrethroid compounds most commonly used to treat LLINs are permethrin, alpha-cypermethrin, and deltamethrin.
22			CTN	Conventionally treated nets (CTNs) are mosquito nets that must be re-treated with insecticide periodically to retain their effectiveness. The nets distributed in the trials informing our treatment effect estimates were CTNs.
23			Dual AI nets	Dual active ingredient (Dual AI) nets are LLINs that are treated with multiple insecticidal chemicals that have different mechanisms of action. These nets are typically treated with a pyrethroid plus another insecticide and are designed to combat pyrethroid-resistant mosquitoes.
24			PBO	Piperonyl butoxide (PBO) is a chemical used alongside pyrethroid insecticides to treat some types of LLINs ("PBO nets") to enhance their effectiveness against insecticide-resistant mosquitos. PBO is not itself an insecticidal chemical but acts as a "synergist" that inhibits the metabolic enzymes that grant mosquitoes immunity to pyrethroids.
25			Chlorfenapyr	The rate of new cases in a given unit of time.
26			Incidence
27			Prevalence	The proportion of people with a disease or condition at or during a particular time period (regardless of when they first contracted it).
28			Indirect malaria deaths	Deaths in which malaria plays a causal role, but are attributed to another cause. For example, malaria may increase the likelihood of death from malnutrition or other infectious diseases. Malaria control interventions often have a larger effect on all-cause mortality than would be expected exclusively from declines in malaria-specific mortality, which we interpret as evidence that averting malaria may also avert deaths attributed to other causes.
29			Insecticide resistance	Immunity among mosquito populations to the insecticidal chemicals commonly used to treat LLINs. Insecticide resistance can inhibit the protective effect of nets against malaria transmission.
30			Bioassay	An insecticide resistance test that involves exposing mosquitos to an insecticidal chemical and measuring the proportion of mosquitos that are killed.
31			Person-year of effective coverage	We use "effective coverage" to refer to a level of protection against malaria equivalent to the protection provided by the nets distributed in the mortality studies we rely on. A "person-year" refers to the equivalent of one person receiving one year of effective coverage. This unit is a simplification. For example, because nets typically remain effective longer than a year, two person-years of coverage could actually reflect one person receiving effective coverage for two years.
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33		Terms used across GiveWell's CEAs
34			Internal validity	Describes an adjustment we make to the treatment effect of an intervention to account for the possibility that the treatment effects found in studies may not represent the true effect the intervention had on the populations studied.
35			External validity	Describes an adjustment we make to the treatment effect of an intervention to account for differences in the program implementation or populations treated in studies from the program implementation or populations treated by grantee programs.
36			Leverage	Describes a situation where a grantee's spending on a program causes other organizations or governments to contribute more to the program than they otherwise would have. In most cases, accounting for leverage increases cost-effectiveness
37			Funging	Describes a situation where a grantee's spending on a program causes other organizations or governments to contribute less to the program than they otherwise would have. In most cases, accounting for funging decreases cost-effectiveness.
38			In-kind contributions	Describes non-financial (e.g., staff time, office space) contributions to a program that might otherwise have been used for other activities or programs.
39			Counterfactual	In most cases, describes the state of the world that would exist if we did not provide funding to a grantee for a program. When discussing the "counterfactual value of other actors' spending," we are referring to how much benefit another organization's or government's spending would generate if it were spent on something other than the grantee program.
40			Moral weights	To compare cost-effectiveness across different programs, we use ‘moral weights’ to quantify the benefits of different program impacts (e.g. increased income vs reduced deaths). We benchmark the value of each benefit to a value of 1, which we define as the value of doubling someone’s consumption for one year.
41			Philanthropic actors	Non-governmental organizations (NGOs) providing funding to philanthropic programs.
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43	Unit and source key
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45		Unit labels used in the CEA
46			#	Number
47			per 1k	Rate per 1,000
48			per 100k	Rate per 100,000
49			$	U.S. dollars
50			ln($)	The natural logarithm of a monetary value
51			%	Percentage
52			ppt	Percentage points
53			UoV	Units of value: an arbitrary unit GiveWell uses to compare the moral value of different types of outcomes, such as saving lives or increasing income
54			xbenchmark	Cost-effectiveness in terms of multiples of GiveWell's benchmark
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56		Source labels used in the CEA
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58			Input	A value pulled from the "Inputs" sheet
59			Calc	A value calculated using other values in the same sheet
60			Supp	A value pulled from one of the sheets hosting supplemental calculations
61			Main	A value pulled from the "Main CEA" sheet
62			Feed	A value pulled from an earlier section within the same sheet
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64	GiveWell analyses informing this model
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66		Analyses specific to this CEA
67			GW's model of LLIN coverage years compared to CTNs
68			GW's insecticide resistance analysis
69			GW's analysis of counterfactual scenarios on pre-existing nets
70			GW's subnational counterfactual mortality calculations
71			Updated GiveWell summary of ITN RCTs
72			GW's analysis of the number of people covered per net
73			GW's analysis of AMF net purchases by net type
74			GW's analysis of Nigerian state-level population estimates
75			GW's analysis of DRC net durability
76			GW's analysis of malaria development effects size
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78		Analyses referenced across GiveWell's CEAs
79			GW's moral weights and discount rate
80			GW's analysis on estimating multiplier for benefits experienced by other household members
81			GW's supplemental intervention-level adjustments
82			GWs benchmark for evaluating cost effectiveness
83			GW's analysis of the counterfactual value of other actors' spending
84			GW's analysis of the counterfactual value of Global Fund spending
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