Ten Miles Square


March 19, 2013 11:13 AM Why The Prison Population is Falling

By Keith Humphreys

I was glad to see that my post on the declining rate of incarceration in the U.S. was picked up by a number of other blogs and newspapers. In those fora, a number of people argued that the recent decrease is simply a function of state budgets being tight. The Pew Charitable Trusts has a thoughtful analysis out suggesting that it is more complex than that.

The number of people incarcerated went up every single year from the mid 1970s until 2009. Over that more than 30 year period, there have been economic booms and contractions, changes in the relative strength of the major political parties, alterations in the demographic makeup of the US general population, the waxing and waning of drug epidemics, and countless other changes in American life. What that should tell us is that any simple explanation for why America has the prison policy it does at any given time is wrong or at least incomplete.

Pew notes that over the past 5 years, incarceration fell in 29 states (ruling out another simple explanation: that this is all due to the court order to reduce overcrowding in California prisons). The factors Pew describes as important are

(1) The evident success of states like Texas which have reduced imprisonment, costs and crime at the same time

(2) Widespread public/political support for reduced incarceration, including among influential conservatives

(3) Research-based alternatives to prison. These include “swift-and-certain” probation and parole initiatives such as HOPE Probation and 24/7 sobriety, both of which have been touted by the Obama Administration.

To Pew’s list, it would be reasonable to add the aging of the incarcerated population because older prisoners are unlikely to re-offend after release. Also important have been the sharp reduction in crime and attendant decline in public fear of victimization, and, the almost total disappearance in Washington and many state capitols of lock-em-up rhetoric regarding low-level drug crimes.

[Originally posted at The Reality-based Community]

Keith Humphreys is a professor of psychiatry and behavioral medicine at the Stanford University School of Medicine.


  • Tom on March 19, 2013 1:48 PM:


    You have missed what may be the most significant factor: reduction of lead in the environment. Kevin Drum at Mother Jones has been on top of this for a long time:


  • low-tech cyclist on March 19, 2013 7:05 PM:

    And one place the effect of lead reduction shows up is in the aging of the prison population: lots of onetime youthful offenders in prisons are getting older, but for some time now haven't been replaced by nearly as many new youthful offenders.

    After awhile that had to result in declining prison populations, because even with all the lock-em-up fervor of the 1980s and 1990s, eventually those long prison terms from days gone by had to start ending.

    I'm looking forward to private prison corporations going bust in a decade or so.

  • gyrfalcon on March 21, 2013 1:11 AM:

    Wow, seriously, how could you possibly be unaware of Kevin Drum's superb cover piece in Mother Jones a month or so ago about lead poisoning and crime? That's just embarrassing. If you're going to write about this stuff, for heaven's sake *keep up*.

  • LimaBN on March 23, 2013 2:45 AM:

    The current generation of those most likely to offend (18 to 25) has fewer people likely to offend because this generation was born when all forms of birth control were
    most freely available to their mothers.

    Young women who knew their chances of successfully raising children were very poor did not complete those pregnancies.

    But then the culture warriors figured out how they could be powerful and successful, and get rich, by bullying those young women.