TOWARD AN OPTIMAL DECARCERATION STRATEGY.

• Author: Grunwald, Ben

With mounting support for dramatic criminal justice reform, the question is no longer whether we should decarcerate American prisons but how. This question is far more complicated than it might seem. We could cut the prison population in half, for example, by drastically shortening sentences. Or we could reduce prison admissions. Or we could do both. And we could do either or both for countless combinations of criminal offenses. Moreover, even when they reach the same numeric target, these strategies are not equivalent. They would have vastly different consequences for both prisoners and the public, and widely varying timeframes to take effect. To pick among them, we need richer metrics and more precise empirical estimates to evaluate their consequences.

This Article begins by proposing metrics to evaluate the relative merits of competing decarceration strategies. The public debate has focused almost exclusively on how we might decarcerate while minimizing any increases in crime and has, therefore, underappreciated the costs of prison itself. We should consider at least three more metrics: the social harm of incarceration, racial disparity, and timing. Next, the Article develops an empirical methodology to identify the range of strategies that would reduce the national prison population by 25, 50, and 75%. Finally, it identifies the best performing strategies against each metric.

The results have several broader takeaways. First, the optimal approach to decarceration depends heavily on which metrics we value most. The results thus quantify a stark set of policy choices behind a seemingly simple objective. Second, the results confirm that, to dramatically shrink prisons, it is critical to decarcerate a substantial number of people convicted of violent offenses--a fact that may surprise the majority of Americans who believe people convicted of drug offenses occupy half of prison beds. Finally, the results show that race-neutral decarceration strategies are likely to exacerbate rather than mitigate racial disparities. Armed with the conceptual tools and methodologies developed in this Article, we can make more informed decisions about how to best scale down prisons, given our priorities and constraints.

INTRODUCTION 3 I. METRICS OF DECARCERATION 9 A. Crime 10 B. Social Harm 13 C. Racial Disparity 16 D. Timing 18 II. DATA 19 III. DESCRIBING STATE PRISONERS 21 A. Demographics 21 B. Criminal Offenses 24 C. Time Served 25 D. International Comparison 26 IV. FORECASTING DECARCERATION 28 A. Methodology 29 B. Primary Results 34 C. Summary of Best Options 44 D. Accounting for Diminished Deterrence & Incapacitation 47 V. IMPLICATIONS AND TAKEAWAYS 49 A. A Few Guiding Principles 49 B. Decarceration's Priorities 50 C. Violent Offenses & Racial Disparities 52 D. Feedback Effects of Diminished Deterrence & Incapacitation 58 CONCLUSION 58 APPENDIX A. ADDITIONAL TABLES AND FIGURES 59 APPENDIX B. SUPPLEMENTARY ANALYSES 63 APPENDIX C. ACCOUNTING FOR DIMINISHED DETERRENCE AND INCAPACITATION 77 INTRODUCTION

The numbers are all too familiar. The United States imprisons 2.3 million people--almost 1% of its residents, more than any other country in the world, and over four times more per capita than fifty years ago. (1) Half of prisoners released will return within three years. (2) People of color are vastly overrepresented, with Black and Latinx residents incarcerated at rates five and three times higher than white residents. (3) So too are the poor. Before their incarceration, prisoners' median annual income is 41% lower than that of people of the same age on the outside. (4) And far too many have serious mental health issues. (5) Jails and prisons are also brutal places, with high rates of physical and sexual violence committed by both inmates and staff. (6) And there's little evidence that much of the rise in incarceration over the last forty years--particularly during the 1990s--substantially reduced crime. (7)

All of these statements have been true for decades. But after the murder of George Floyd and the protests that followed, there has been renewed optimism about the possibility of dramatic criminal justice reform. The consensus is growing that we have far too many people behind bars, even more so since the spread of COVID-19, which has killed thousands of prisoners and infected hundreds of thousands more. (8)

Among academics and activists, two rich literatures appear to be gaining ground. The first is written by abolitionists like Angela Davis, Ruth Wilson Gilmore, Mariame Kaba, Beth Ritchie, and others. (9) They argue that, given the massive social costs of prison, its historical connections to slavery, and its social and racial inequalities today, the ultimate goal of a democratic society must be to restructure economic conditions such that prison is no longer necessary. (10) They envision massive investment in community infrastructure and an overhaul of criminal justice towards decriminalization, restorative justice, treatment programs, and community control. (11) A second literature, written largely by legal scholars and criminologists, dives into the procedural details, identifying specific legal tools like sentencing and parole reforms that could be used to engineer decarceration. (12)

There are weak signals that large-scale decarceration is slowly creeping into the mainstream, too. (13) During the 2020 presidential primary, for example, at least five major Democratic candidates--Cory Booker, Pete Buttigieg, Julian Castro, Tulsi Gabbard, and Beto O'Rourke--"committed to reducing incarceration by half" at public campaign events. (14)

Yet, even among scholars and activists who support large-scale reductions in the prison population, there's little consensus on who we should decarcerate and how. Indeed, there are many ways to reduce the prison population by a given quantity; we could shorten sentences or we could reduce admissions, and we could do either for countless combinations of offenses. But, critically, these strategies are not equivalent. They could have vastly different social consequences even if they would achieve the same numeric reduction in the prison population. To pick among them, we need richer metrics and more precise empirical estimates of the varied consequences of decarceration strategies.

This paper proposes metrics to assess the relative merits of different decar-ceration strategies and puts them to the test. The mainstream public debate has focused almost exclusively on a single metric: minimizing increases in crime. In doing so, it has underappreciated the costs of prison itself. (15) In evaluating decarceration strategies, we should consider at least three additional metrics.

First, and admittedly sometimes in tension with the metric of crime, decarceration should seek to minimize the social harms of prison. As Dorothy Roberts and others have argued, incarceration imposes enormous costs on prisoners, their families, and their communities, particularly among Black people and other people of color. (16) Incarceration disrupts education and careers; separates families; exposes prisoners to disease, violence, and trauma; disenfranchises; and, for some people, it may even be criminogenic. (17) Many of these harms cluster at the moment of entry into prison, which means there are unique benefits to decarceration strategies that keep people out altogether. To be clear, social harm need not be a secondary metric relative to crime. Indeed, the relevant harms are sufficiently large that some scholars and activists would prefer the risk of higher crime over that of continued mass incarceration, as long as the communities most affected support that tradeoff. (18)

Second, decarceration strategies should, to the extent possible, minimize racial disparities behind bars. As noted, people of color are vastly overrepresented in prison. (19) These disparities have long historical roots, dating back to the end of slavery. (20) And they have been exacerbated by more recent criminal justice policies, including the war on drugs, order maintenance policing, and mandatory minimum sentencing. (21)

Third, we cannot talk about decarceration without also talking about timelines. With the right political will, some strategies could happen almost overnight by cutting time served for both current and future prisoners. On the other hand, approaches that focus on reducing admissions or time served exclusively for future prisoners can take decades to realize, particularly with respect to prisoners with long sentences. Given the fickle dynamics of American politics, decarceration strategies that are quicker--actualized over years, not decades--are probably preferable. Quicker decarceration nonetheless comes with real costs. Perhaps most important, some government officials may be unwilling to support a decarceration strategy if they perceive it does not provide sufficient insulation against political backlash.

With metrics in hand, the Article next develops an empirical methodology to forecast the effects of a wide range of decarceration strategies. Here, I build on prior empirical work in the literature. The only national analysis, published by the Brennan Center for Justice, sought to estimate the number of prisoners at year-end 2012 that it believed could be released "without endangering public safety." (22) The report recommends releasing 39% by eliminating incarceration for low-level crimes and reducing time served for others. (23)

One limitation in this analysis is that a prison system cannot be represented simply by a static population at the end of the year; (24) a prison is also a dynamic flow of new admissions every day. Thus, concluding that we should release 39% of prisoners on a given day doesn't tell us what will happen in the months and years afterwards. To understand the effect of decarceration over the long term, we also need to model flow. (25)

To forecast the effects of decarceration while...