Like most people who write about trends in incarceration, I generally focus on how the size and nature of the entire U.S. prison population changes from year to year (e.g., here and here). This sort of analysis can reveal important things, for example that after rising every year for more than three decades, the size of the prison population has been dropping for three years in a row. But at the same time, such analyses tell us little about what state and federal policymakers are doing regarding prisons right now.
All policymakers are at some level trapped by decision accretion, and prisons are a perfect example of the phenomenon. The high level of incarceration in the U.S. is the product of decisions made over many years prior to when the current group of policymakers was on the scene. For example, while I have complained about the abolition of federal prison parole as a cause of overcrowding, I also recognize that many of the elected officials who voted for it have died of old age, and hardly any are still in office. Even if the current Congress re-established parole tomorrow, it would take years to unring that bell. Likewise, people who have committed heinous crimes for which they are serving multi-decade sentences do not simply evaporate with each election. And that’s critically important in evaluating how quickly current policymakers can reduce incarceration levels given that the majority of the state prison population is composed of violent offenders who are serving long sentences.
To try to get around this analytic problem of decision accretion swamping recent trends, I used the latest Bureau of Justice Statistics data to compute the annual rate of admissions to state/federal prison. As the chart below reveals, the large amount of recent change in this variable was obscured in my prior analyses, which looked only at total prison population size. I was startled and encouraged to see that under current policies, we are at a two decade-year low in the prison admission rate. To provide historical perspective, peg the change to Presidential terms: When President Obama was elected, the rate of prison admission was just 3% below its 2006 level, which was very probably the highest it has ever been in U.S. history. But by the end of Obama’s first term, it had dropped to a level not seen since President Clinton’s first year in office.