Naked statistical evidence and incentives for lawful conduct

Abstract

The problem of ‘naked statistical evidence’ is one of the most debated issues in evidence theory. Most evidence scholars agree that it is deeply problematic to base a verdict on naked statistical evidence, but they disagree on why it is problematic, and point to different characteristics of naked statistical evidence as the root of the problem. In this article, the author discusses the merits of different solutions to the problem of naked statistical evidence, and argues for the incentive-solution: verdicts based on naked statistical evidence are unacceptable as they do not contribute in a positive way to the incentive structure for lawful behaviour.

When statistical evidence is not specific enough

“…They offer the additional information that 99 of the 100 workers in the factory killed the guard. For a similar analysis of naked statistical evidence, see Dahlman (2020). This formulation makes clear that the first-order information bearing on the incident-namely the testimony that the worker was in the factory-cannot be specific enough to sustain a homicide accusation.…”

“…In an effort to clarify and reconcile, I will examine different forms of statistical evidence as they are used in criminal trials. For the sake of readability, this 1 See, for example, Tribe (1971); Nesson (1979); Cohen (1977); Thomson (1986); Wasserman (1991); Stein (2005); Ho (2008); Enoch et al (2012); Cheng (2013); Buchak (2014); Pritchard (2015); Blome-Tillmann (2015); Nunn (2015); Staffel (2016); Smith (2018); Pundik (2017); Littlejohn (2020); Gardiner (2018); Di Bello (2019); Dahlman (2020); Bolinger (2020); Moss (2021); Nelkin (forthcoming).…”

Statistical evidence and the criminal verdict asymmetry

“…3 Though a few scholars support the inclusion of statistical evidence across the board, the more commonly-held view is that there is something troubling about statistical evidence in legal contexts, and especially so in the context of criminal trials. (Allen, 1990;Blome-Tillmann, 2015, 2017Bolinger, 2020;Cheng, 2012;Cohen, 1977;Colyvan et al, 2001;Dahlman, 2020;Dant, 1988;Di Bello, 2019Enoch & Fisher, 2015;Enoch et al, 2012;Fienberg & Schervish, 1986;Gardiner, 2018Gardiner, , 2020Koehler, 2002;Moss, 2018Moss, , 2021Nance, 2016;Nesson, 1984;Nunn, 2015;Pardo, 2005Pardo, , 2010Pardo, , 2018Pardo, , 2019Pundik, 2008Pundik, , 2011Pundik, , 2021Redmayne, 2008;Smith, 2018;Thomson, 1986;Tribe, 1971;Twining, 1980;Wasserman, 1991;Wright, 1988;). 4 The concerns regarding statistical evidence in legal contexts fall roughly into two categories: epistemic and moral.…”

Statistical evidence and incentives in the law

“…1616The Uviller/Sanchirico distinction between trace evidence and predictive evidence features in Dahlmann (2020)’s discussion of incentives and statistical evidence. But having made the abstract distinction between “cases with only naked statistical evidence and cases with a mix of naked statistical evidence and trace evidence”, he classifies the blue bus case as one where “there is only naked statistical evidence” (p. 165).…”

“…2020Dahlmann (2020, p. 176) remarks that the statistical evidence regime “‘gives companies with a minor market share an incentive to be opportunistic and act negligently, since the consequences of such behavior is carried by the company with the major market share.” He then suggests that “it is reasonable to assume” that this negative effect “is stronger than the positive effect of the incentive structure of the company with the major market share, and this means that the net‐effect is negative”. In support of this verdict of comparative strength, he suggests that the incentive for the Blue Bus Company might not be very strong since the greater market share company would “have to pay for all the accidents caused by the negligence” of the lesser market share company.…”