The 2003 Washington State Legislature directed the Institute to analyze how sentences for adult felons affect the state’s prison population. Our task is to determine whether policy changes to Washington’s sentencing structure could reduce the growth in the prison population without jeopardizing public safety. Our findings are published in three parts. Part I, published in March 2004, reviewed the sentencing structure for Washington and examined the growth of the prison population. Part III will summarize the study’s findings. This report, Part II, examines the statistically estimated impact of imprisonment and sentence lengths on recidivism. That is, do offenders sentenced to prison, and those who receive longer prison sentences, recidivate more or less often than similar offenders not sentenced to prison or who receive shorter sentences? Can these policy levers be adjusted to reduce prison populations without adversely affecting public safety?