If you want to split hairs and define “town” as “the current Austin city limits,” of course you're absolutely right. Under that definition, the number of people moving “to town” between now and 2035 would be only about 332,344. But please consider that our statement wasn't about residency; it was about demand for city services and the scope of problems we need to solve.
The truth is, the City of Austin doesn't only provide services to residents. Something like 70% of jobs in the five-county MSA are inside the Austin city limits. The number of people moving to the MSA is approximately 1.6 million. The vast majority of these people (probably well over a million) will depend in whole or in part on the City for their livelihood. Even if new residents of San Marcos, Georgetown, Luling, or Bastrop don't work in Austin, many of them will visit Austin regularly to shop, find health care, or have a good time. While they're here, these people will depend on the City of Austin for public safety, water and sewer, solid waste, flood control, parks, and of course electricity.
The city council's problems don't stop at the city limits, either. The housing market is regional; so are our transportation problems. Every one of those 1.6 million moving into the central Texas region (I would argue, “to town”) will be increasing demand for housing and increasing the load on the regional highway network; if the projected regional population increase were only 330,000, we wouldn't be facing anywhere near the same housing affordability and traffic congestion problems. I'm tempted to state that every one of those 1.6 million new residents will spend time on I35, but this would probably only prompt you to track down some eccentric Liberty Hill cedar chopper who rides his horse to the local HEB, and I've got to get my grades done.
Split hairs if you like, but please recognize our basic point: A whole bunch of people are moving to the Austin-Round Rock-San Marcos Metropolitan Statistical Area. This increase puts a great strain on the City of Austin's physical, economic, and social infrastructure and gives the Austin City Council a lot of work to do. If we can more effectively fulfill our responsibilities by delegating some of this work to a group of carefully chosen citizens who share our values but have greater expertise – and that is our proposal – then we should do so.
Let me know if you need more footnotes.
Member, Austin City Council and
Professor, LBJ School of Public Affairs, University of Texas at Austin
 Per Ryan Robinson, City of Austin demographer, the best estimate for the population with current city limits is 1,175,094. Subtract the current population of 842,750 leaves 332,344 (austintexas.gov/sites/default/files/files/Planning/Demographics/austin_forecast_2013_annual_pub.pdf ).
 Our actual statement: “The council hasn’t got that kind of attention. We’ve got 20-odd departments to watch over and — with nearly a million people coming to town in the next 20 years — incredible housing, land use, and transportation problems. A good manager wouldn’t try and tackle all these issues herself. She’d delegate some of them to people she can trust. And that’s what we’re trying to do” (Leffingwell and Spelman, “Independent board would save Austin Energy,” Austin American-Statesman (5 May 2013).
 Specifically, citing the most recent Economic Census (2007) from American Fact Finder (factfinder2.census.gov), we find that 347,235 jobs were in the City of Austin, out of a total of 494,491 jobs in the Austin-Round Rock-San Marcos MSA. That's 70.22 percent.
 City of Austin projections for the five-county MSA for 2035 are 3,481,592 (http://www.austintexas.gov/sites/default/files/files/Planning/Demographics/austin_forecast_2013_annual_pub.pdf ). The current estimates for the MSA is 1,870,872 (same source). That's a difference of 1,610,720.
 .7022 ´ 1,610,720 = 1,131,058.7, well over 1 million. Although Austin's percentage of MSA jobs is slowly decreasing, so long as it stays over 62.08 percent the “depend on Austin for their livelihood number” will be over 1 million.
 Health care establishments in the City of Austin added $5,232,094,000 in value during 2007 (Economic Census, factfinder2.census.gov). Health care establishments throughout the five-county MSA added $7,015,576,000 during the same period. So Austin represents 74.58% of all health care delivered in the region. I use value added here because it better measures the extent and cost of services provided; if you only use employment, Austin represents 68.60% of health care delivered. The Economic Census of 2007 also shows that the value added by arts, entertainment, and recreation establishments in the City of Austin is 67.39 percent of the entire region (62.99 percent if estimate by employment). Value added by retail establishments in the City of Austin is $13,493,511,000, 50.47 percent of the MSA (59.93 percent if estimate by employment).
 As a recent Brookings Institution paper on housing affordability put it, “In an era of population and employment decentralization, the metropolitan area—not the individual political jurisdiction—represents the appropriate level at which to think about and act on access to affordable housing.” Bruce Katz and Marjorie Austin Turner, “Rethinking local affordable housing strategies: Lessons from 70 years of policy and practice,” Research Brief (Washington, DC: The Brookings Institution and the Urban Institute, Dec 2003), p. 6.
 “Traffic congestion is essentially a regional phenomenon requiring regional approaches to mitigate its impacts.” Anthony Downs, “The need for regional anti-congestion policies,” The Brookings Institution Series on Transportation Reform (Washington, DC: The Brookings Institution, Feb 2004), p. 1.