[USA] Public Safety, Public Spending: Forecasting America’s Prison Population 2007–2011 / The Pew Charitable Trusts, 14 February 2007
PDF - http://www.pewtrusts.com/pdf/PSPP_prison_projections_0207.pdf

[USA] Study predicts rise in inmate populations / USA Today, 14 February 2007
http://www.usatoday.com/news/nation/2007-02-13-prisons_x.htm
Kevin Johnson
"The number of inmates in US prisons likely will rise nearly 13% during the next five years, costing states up to $27.5 billion in new operating and construction expenses."