One and Only

In 1950, according to the Census Bureau, the percent of U.S. households that consisted of one person living alone was 9.3. In 2000, that number was 26 ~ about 27.2 million Americans. In his new book, "Going Solo: The Extraordinary Rise and Surprising Appeal of Living Alone," NYU sociology professor Eric Klinenberg talks about the many factors that have contributed to that change: http://www.economist.com/blogs/prospero/2012/02/qa-eric-klinenberg
For more on the topic: http://www.nytimes.com/2012/02/23/garden/the-freedom-and-perils-of-living-alone.html?_r=1