Why Are So Many Americans in Prison?

March 2007

Steven Raphael, University of California, Berkeley and Michael A. Stoll, University of California, Los Angeles.

Download 'working_paper07-10.pdf'.


The United States currently incarcerates its residents at a rate that is greater than every other country in the world. Aggregating the state and federal prison populations as well as inmates in local jails, there were 737 inmates per 100,000 U.S. residents in 2005 (International Centre for Prison Studies 2007). This compares with a world average of 166 per 100,000 and an average among European Community member states of 135. Of the approximately 2.1 million U.S. residents incarcerated in 2005, roughly 65 percent were inmates in state and federal prisons while the remaining 35 percent resided in local jails.

Moreover, current U.S. incarceration rates are unusually high relative to historical figures for the U.S. itself. For the fifty year period spanning the 1920s through the mid 1970s, the number of state and federal prisoners per 100,000 varied within a 10 to 20 unit band around a rate of approximately 110. Beginning in the mid 1970s, however, state prison populations grew at an unprecedented rate, nearly quadrupling between the mid 1970s and the present. Concurrently, the rate of incarceration in local jails more than tripled.

Crime, Incarceration, and the Labor Market