Empirical Legal Studies

15th Annual Conference on Empirical Legal Studies (CELS)

Given the many disruptions incident to the COVID-19 pandemic, I am nothing short of delighted to announce that the Fifteenth Annual Conference on Empirical Legal Studies (CELS), presented by the Society for Empirical Legal Studies (SELS) and hosted by the University of Toronto Faculty of Law (Canada), is now scheduled for Friday, March 18, and Saturday, March 19, 2022.

CELS brings together scholars from an array of fields, including law, economics, political science, psychology, statistics, sociology, history, and policy analysis. Papers are selected through a peer-review process and each is assigned an individual discussant. CELS invites empirical papers that span all areas of empirical legal studies. Authors are encouraged to submit works-in-progress; however, submissions should be completed paper drafts that include main results. Submitted papers must also be unpublished (and are expected to be unpublished at the time of the conference). The paper submission portal will open August 1, 2021. The deadline for submissions is October 17, 2021.

Of course, while the conference organizers plan on (and sincerely hope for) an in-person event, given the ongoing uncertainties participants are urged to delay purchasing any non-refundable airline tickets at this moment. Additional conference information is found here.

A Descriptive Glance at Police Clearance Rates

While I have an admitted affinity for asking simple questions, sometimes it's the "simple" question that can help point the way toward more sophisticated empirical work. A recent paper by Andrew Leipold (Ill.), The Puzzle of Clearance Rates, and What They Can Tell Us About Crime, Police Reform, and Criminal Justice, makes my point.

The paper begins by framing its core research question: "Recent incidents of police violence have led to widespread reform efforts, from modest proposals to change police practices to dramatic attempts to slash funding or abolish the police entirely. But largely ignored in the debate is a simple question – how well is law enforcement currently performing its core functions? In particular, how good are the police at finding the perpetrator, arresting that person, and gathering enough evidence to start the matter through the criminal justice system?"

Exploring police clearance rate data engages the question. And what Leipold finds is that "Clearance rates for violent and property crimes have been both quite low and amazingly steady for the last 40 years. These figures are counterintuitive, because during that same period, crime first rose and then decreased dramatically; law enforcement personnel numbers increased, and then flattened; and the legal enforcement landscape appears to have tilted in the direction of the police and prosecution. Each of these changes should have significantly affected the clearance rates, but even collectively, they did not."

The presentation of basic descriptive trend data amply supports Leipold's point. And what he argues is that "[w]hile there is no single explanation, the diversion of resources from index crimes and a change in focus toward crime prevention seem to have the most explanatory power." While how to interpret--or explain--the counterintuitive trends, of course, remains ripe for future work, part of the power of initial descriptive work is that it helps bring into sharper relief avenues for deeper and more methodologically sophisticated future research.

The Empirics of Rule 23(f)

While civil procedure scholars have spilled a lot of ink on class actions, until quite recently little of it is informed by data. To help remedy this, in a recent paper, Class Certification in the U.S. Courts of Appeals: A Longitudinal Study, Stephen Burbank (Penn) and Sean Farhang (Berkeley) exploit a class certification decision data set that includes USCA precedential panel decisions (1966 through 2017) and nonprecedential panel decisions (2002 through 2017). The data permit the authors to test various "conventional wisdoms," including those related to class certification appeal outcomes and Rule 23(f)'s potential influence. Among their findings includes, e.g., that, "contrary to conventional expectations, in the period since Wal-Mart and Comcast, plaintiffs have been winning certification appeals more frequently than they were formerly, and Rule 23(f) contributed to this recent success." More specifically, the paper notes "significant variation over time in appeal outcomes under Rule 23(f), with defendants far more successful than plaintiffs prior to Wal-Mart and Comcast, and relative parity after." An excerpted abstract follows.

“There is a vast literature on the modern class action, but little of it is informed by systematic empirical data. Mindful both that there have been few Supreme Court class certification decisions and that they may not provide an accurate picture of class action jurisprudence, let alone class action activity, over time, we created a comprehensive data set of class certification decisions in the United States Courts of Appeals consisting of all precedential panel decisions addressing whether a class should be certified from 1966 through 2017, and of nonprecedential panel decisions from 2002 through 2017.

…

We find significant variation over time in appeal outcomes under Rule 23(f), with defendants far more successful than plaintiffs prior to Wal-Mart and Comcast, and relative parity after. This variation suggests the hazards of generalizing about operation of that rule from experience in any particular period. Our models also show that, for reasons about which we can only speculate, interlocutory appeals since around 2000 have elicited more ideological voting behavior by judges, leading to greater polarization.”

Count data, Logging Zeros, and Poisson

A persistent issue confounding many empirical legal studies using count data involves the "zeros problem," especially when the count data require a log transformation. Contests on how to best deal with this problem persist. Popular approaches include standard OLS regression models that add a "plus one" to each count data so to not lose all cases with a zero count in the log transformation and Poisson regressions models.

While empirical assessments of these two approaches are relatively rare, a recent paper compares these two approaches drawing on replication analyses of five recent corporate patenting papers. In Count Data in Finance, Jonathan Cohn (Texas--Business) et al., find that one OLS regression approach (LOG1PLUS) "using log-transformed outcomes can produce biased and incorrectly signed estimates of economic relationships and provide guidance for future research in finance-related applications involving zero-bounded count data." By comparison, while the Poisson model estimates may "lose efficiency if the model’s conditional mean-variance equality restriction is not satisfied in the data, they remain unbiased and consistent as long as the standard conditional mean independence assumption holds." The paper's abstract follows.

"This paper examines the use of count data-based outcome variables such as corporate patents in empirical corporate finance research. We demonstrate that the common practice of regressing the log of one plus the count on covariates (“LOG1PLUS” regression) produces biased and inconsistent estimates of objects of interest and lacks meaningful interpretation. Poisson regressions have simple interpretations and produce unbiased and consistent estimates under standard exogeneity assumptions, though they lose efficiency if the count data is overdispersed. Replicating several recent papers on corporate patenting, we find that LOG1PLUS and Poisson regressions frequently produce meaningfully different estimates and that bias in LOG1PLUS regressions is likely large."

Life Sentences "With" or "Without"

While significant public and scholarly attention rightly dwells on capital punishment, comparatively under-explored is a steady surge of life sentences without the possibility of parole ("LWOP"). While the Furman Court's "death is different" doctrine retains obvious salience and moral force, it should not obscure LWOPs from much-needed empirical inquiry.

To this end, in a recent paper, Life 'With' or 'Without'?: An Empirical Study of Homicide Sentencing, forthcoming in JELS, Michael O'Hear (Marquette) and Darren Wheelock (Marquette--Dept. Social and Cultural Sciences) do just that. While the paper's data set is limited to Wisconsin homicides, the authors do a deep data dive into 450 individuals convicted of first-degree intentional homicide between the start of 2001 and about mid-2018. The core findings are mixed. On the one hand, "intentional-homicide defendants who have more serious criminal histories are more likely to receive LWOP." On the other hand, "sentencing outcomes are influenced by the identity of the judge and prosecutor." The paper's abstract follows.

"The number of Americans serving sentences of life without the possibility of parole (“LWOP”) has grown rapidly over the past generation and now exceeds 50,000. Yet, little empirical research has been conducted on the determinants of LWOP sentences. The dearth of research on LWOP sentencing stands in sharp contrast to the many dozens of studies that have been conducted on the determinants of death sentences—studies that have consistently found that race, gender, and other questionable factors may influence sentencing outcomes. The present study is the first to employ a similar methodology to identify both case- and county-level variables that are correlated with the imposition of discretionary LWOP sentences.

More specifically, we have assessed the relationship between fifty different variables and LWOP decisions in 450 homicide cases in Wisconsin between 2001 and 2018. In our final model, we find seven variables that are correlated with sentencing outcomes. Of particular note, we find that judge and prosecutor personal characteristics are statistically significant correlates of LWOP decisions. We also find a significantly greater likelihood that LWOP sentences will be imposed in counties that are more Republican. We conclude with a proposal for a new LWOP sentencing process that may help to ensure that this very severe sentence is reserved for the most serious crimes committed by the most dangerous defendants."