Deadly Statistics: Quantifying an 'Unacceptable Risk' in Capital Punishment

Law, Probability & Risk, Vol. 16, No. 1, Mar. 2017, pp. 7-34

Penn State Law Research Paper No. 14-2016

38 Pages Posted: 5 Jun 2016 Last revised: 13 Aug 2017

See all articles by David H. Kaye

David H. Kaye

Pennsylvania State University, Penn State Law; Arizona State University - Sandra Day O'Connor College of Law - School of Life Science

Date Written: May 31, 2016

Abstract

In Atkins v. Virginia, the Supreme Court held that the Eighth Amendment ban on cruel and unusual punishment precludes capital punishment for intellectually disabled offenders. Death-penalty states responded with laws defining intellectual disability in various ways. In Hall v. Florida, the Court narrowly struck down the use of a measured IQ of 70 to mark the upper limit of intellectual disability because it created “an unacceptable risk that persons with intellectual disability will be executed.” But the Court was unclear if not inconsistent in its description of an upper limit that would be acceptable. Four dissenting Justices accused the majority not only of misconstruing the Eighth Amendment, but also of misunderstanding elementary statistics and psychometrics. This article uses more complete statistical reasoning to explicate the Court’s concept of unacceptable risk. It describes better ways to control the risk of error than the Court’s confidence intervals, and it argues that, to the extent that the Eighth Amendment allows any quantitative cut score in determining an offender’s intellectual disability, these more technically appropriate methods are constitutionally permissible.

Keywords: Hall v. Florida, cruel and unusual, Eighth Amendment, capital punishment, intellectual disability, IQ, psychometrics, cut-score, measurement error, standard error, confidence interval, shrinkage estimator, Bayesian inference, credible region, burden of persuasion

JEL Classification: C11, C12, C13

Suggested Citation

Kaye, David H., Deadly Statistics: Quantifying an 'Unacceptable Risk' in Capital Punishment (May 31, 2016). Law, Probability & Risk, Vol. 16, No. 1, Mar. 2017, pp. 7-34; Penn State Law Research Paper No. 14-2016. Available at SSRN: https://ssrn.com/abstract=2788377

David H. Kaye (Contact Author)

Pennsylvania State University, Penn State Law ( email )

University Park, PA 16802
United States

HOME PAGE: http://www.personal.psu.edu/dhk3/index.htm

Arizona State University - Sandra Day O'Connor College of Law - School of Life Science ( email )

111 E Taylor St.
Phoenix, AZ 85004
United States

HOME PAGE: http://www.personal.psu.edu/dhk3/index.htm

Register to save articles to
your library

Register

Paper statistics

Downloads
122
Abstract Views
684
rank
228,803
PlumX Metrics