More than 80 percent of the United States' population lives in urban areas, and the urban population grew by 12.1 percent between 2000 and 2010. (1) The fact th

More than 80 percent of the United States' population lives in urban areas, and the urban population grew by 12.1 percent between 2000 and 2010. (1) The fact that some towns are underpopulated doesn't mitigate overcrowding in cities because we can't assume that urban families are willing or able to relocate to rural areas. You wrote that "housing stock, food output and economic activity" have risen, but evidence suggests that have not risen at a rate proportional to the population growth in America's largest cities. National Geographic wrote a nice general article about the economic & environmental problems caused by overpopulation, using Fresno, CA, as an example.(2) Some specific examples: New York City's public schools were 200 percent over capacity as of 2008 (3). A 2012 study showed that 21 major American cities had experienced an increase in hunger and homelessness. (4) (1) http://www.census.gov/newsroom/releases/archives/2010_census http://www.census.gov/newsroom/releases/archives/2010_census (2) : http://environment.nationalgeographic.com/environment/habitats/urban-threats2/ http://environment.nationalgeographic.com/environment/habita... (3) http://www.nydailynews.com/new-york/education/new-york-city-schools-suffer-massive-overcrowding-statistics-show-article-1.298837 http://www.nydailynews.com/new-york/education/new-york-city-... (4) http://www.reuters.com/article/2012/12/20/us-usa-economy-hunger-idUSBRE8BJ14I20121220 http://www.reuters.com/article/2012/12/20/us-usa-economy-hun...