Thanks to Thinking Outside the Cage for pointing out an excellent new meta-analysis from the Vera Institute, described as "a 45-year-old nonprofit organization that works on safety and justice issues and is headed by Michael Jacobson, who ran New York City's jails and probation system for Mayor Rudolph Giuliani," on the effectiveness of incarceration vs. other alternative crime fighting approaches
Their public policy report released in January, Reconsidering Incarceration: New Directions for Reducing Crime, relies heavily on UT-Austin criminologist and former Austin city councilmember Bill Spelman's research, particularly his widely quoted estimate that a ten percent increase in incarceration leads to a 2-4 percent reduction in crime.
Bill and I have gone around a little over those stats awhile back, and Vera's analysis captures some of my own discomfort at the results - because they're utterly ambiguous they prove little, or more accurately, they confirm whatever preconceived notion you may already have about whether or not prisons "work" to reduce crime. Whatever your view, Bill's findings confirm them if you dig around in the numbers enough. As the report noted,
Supporters take the findings as a confirmation that prison works, concluding that every 10 percent increase in incarceration rates will produce a 2 to 4 percent decrease in crime rates. Opponents, on the other hand, see the findings as a confirmation that prison does not work very well at all. They maintain that even a 4 percent decrease in crime is not much for a 10 percent increase in incarceration.38 Indeed, Spelman himself characterizes a 2 to 4 percent crime reduction as a fairly limited impact given the sizable financial obligation states have incurred in incarcerating so many people.Given that central conundrum in Spelman's findings, I was happy to see Vera go on to cite additional research I hadn't seen before that I think better characterizes the more fluid, less certain reality of incarceration's effectiveness - bottom line, it's only effective up to a point:
Raymond Liedka, Anne Piehl, and Bert Useem have confirmed, moreover, that increases in prison populations in states with already large prison populations have less impact on crime than increases in states with smaller prison populations. States experience “accelerating declining marginal returns, that is, a percent reduction in crime that gets ever smaller with ever larger prison populations,” they argue. Thus, increases in incarceration rates are associated with lower crime rates at low levels of imprisonment, but the size of that association shrinks as incarceration rates get bigger. Eventually, they say, there is an “inflection point” where increases in incarceration rates are associated with higher crime rates. This inflection point occurs when a state’s incarceration rate reaches some point between 325 and 492 inmates per 100,000 people. In other words, states with incarceration rates above this range can expect to experience higher crime rates with future increases in incarceration rates.So by that estimate, once the incarceration rate exceeds "between 325 and 492 inmates per 100,000 people," you hit a tipping point and crime actually starts to increase with more imprisonment. Texas' current incarceration rate is greater than 1,000 per 100,000 adults. So what does that tell you about the wisdom of more prison building? As indicated in the report's title, it's high time to reconsider incarceration. As Vera concluded:
Public safety cannot be achieved only by responding to crime after it occurs; research shows that it may also depend on protecting people against those factors that have been shown to be associated with high crime rates, such as unemployment, poverty, and illiteracy. By pursuing crime reduction chiefly through incarceration, states are forgoing the opportunity to invest in these other important areas. As state policymakers continue to feel pressure to introduce measures to keep crime rates low, they would therefore do well to look beyond incarceration for alternative policies that not only may be able to accomplish the important task of protecting public safety, but may do so more efficiently and more effectively.I agree. And on that note, it might be a good time to link to Grits' "Real Public Safety Agenda for Texas," in case Texas legislators may be looking for public safety investments that don't involve bricks and mortar.