In 2012 the US incarcerated 2.2 million individuals. That is five times the average incarceration rate of OECD nations. This article explores some of the reasons for the high rate of incarceration in the US. It would appear that the answer is simple. The incarceration rate rose rapidly beginning in the 1970's; the rate tripled as a result of public policy decisions. The 1970's was a period of civil disobedience and heavy drug use. Getting "tough on crime" became a popular political slogan. Being tough on crime also meant getting tough on drug use. Mandatory sentences became a standard practice in almost every state. Social science research also contributed to the increase in the incarceration rate. An important study by criminologists concluded that rehabilitation did not work. It was better to keep criminals in prison than to release them so that they could commit another crime. The difference between the US incarceration rate and OECD nations was also affected by a weaker social safety net in the US. What the US did not spend on the social safety net was spent on prisons.
The incarceration rate in the US has declined in the last couple of years. Some states have even released prisoners because of overcrowding. The high cost of incarceration may cause many states to reconsider some of their policies which mandate prison sentences.