Comment on Ashley Rubin The Declining Death Penalty in Eighteenth-Century London? The Role of Ecological Fallacy in Lenience-Based Accounts Dan Klerman Conference on Empirical Legal Studies October 25, 2013

Before 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft8,09074%1,24315% Other crimes2,88526%2127% Total10,9751,45513% After 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft29,83981%24618% Other crimes6,81119%68810% Total36, % Theft is vast majority of prosecutions So decline in probability of death sentence for theft Drives overall statistics Masks increase in probability of sentence for other crimes Relatively small change in case composition Is it helpful to describe this as ecological fallacy? Contrast Simpson’s paradox

Before 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft8,00080%160020% Other crimes2,00020%20010% Total10, % After 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft2,00020%50025% Other crimes8,00080%120015% Total10, % Simpson’s Paradox (hypothetical data)

Before 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft8,09074%1,24315% Other crimes2,88526%2127% Total10,9751,45513% After 1718 Prosecutions% of prosecutions Death sentences Probability of death penalty Theft29,83981%24618% Other crimes6,81119%68810% Total36, % Theft is vast majority of prosecutions, so decline in probability of death sentence for theft Drives overall statistics Masks increase in probability of sentence for other crimes Relatively small change in case composition Is it helpful to describe this as ecological fallacy? Contrast Simpson’s paradox Is it problematic to say that legal system became more lenient overall?

Control for Case Strength Maybe non-theft cases got stronger after 1718 – So, given cases of equal strength, system was more lenient even in non-theft cases Maybe theft cases got weaker after 1718 – So, given cases of equal strength, system got harsher in theft cases Potential controls – Value & type of stolen goods – Sex, age & status of offender – Relationship between offender & victim – # of witnesses – Prior convictions – Whether prosecutor or defendant had a lawyer – Literacy

Identify Actors and Mechanisms Jury – Pious perjury increased (only theft?) – Other ways for juries to affect sentence Judge – Sentencing discretion of judge More transportation for theft, but not for other crimes – More or fewer requests for pardons – Greater or lesser stringency in administration of benefit of clergy Legislators – Greater percentage of non-theft crimes eligible for death penalty – Changes in eligibility for transportation and/or benefit of clergy Neighbors – Less petitioning for pardons? Prosecutors – Less charging of capital offenses

Other Questions Why focus on pre/post 1718? – Could test for other breakpoints – Could test for overall/continuous trend Death sentence versus execution? Decision to prosecute – Coroner’s data for homicide

Conclusion Important example of benefit of quantitative analysis of legal history Convincing Additional analysis could make truly outstanding – Control for case quality – Explain which actors & mechanisms were responsible for increase/decrease in leniency