Reformer: A survey of police departments keeps track of the national crime rate, which is the annual number of crimes per 100, 000 people  The survey shows no significant reduction in the crime rate in the past 20 years, but the percentage of the population in prison has increased substantially, and public expenditure on prisons has grown at an alarming rate
This demonstrates that putting more people in prison cannot help to reduce crime
ignores the possibility that the crime rate would have significantly increased if it had not been for the greater rate of imprisonment