Legal scholar Cass Sunstein and researcher Justin Wolfers recently joined in an op-ed piece in the Washington Post responding to the U.S. Supreme Court’s citation of their work in Baze v. Rees, the decision that approved lethal injection and opened the way to recent executions. Justice Stevens had cited Wolfer’s research as evidence of the lack of deterrence of the death penalty while Justice Scalia cited Sunstein’s writings indicating a “a significant body of recent evidence that capital punishment may well have a deterrent effect, possibly a quite powerful one.” Both Sunstein and Wolfers say the Justices “misread the evidence” to “support their competing conclusions on the legal issue.” They explained the nuances of the evidence on deterrence and the death penalty and how no study on the topic can support a strong conclusion. “The best we can say is that homicide rates are not closely associated with capital punishment.” They added, “In short, the best reading of the accumulated data is that they do not establish a deterrent effect of the death penalty.”

This interpretation of the research is important, the authors argue, because it is commonly reasoned that “if capital punishment fails to deter crime, it serves no useful purpose and hence is cruel and unusual,” and many, “including President Bush, argue that the only sound reason for capital punishment is to deter murder.” Sunstein and Wolfers point out that there is no valid study that conclusively shows deterrence and “the debates over the death penalty should not be distorted by a misunderstanding of what the evidence actually shows.”
(C. Sunstein, J. Wolfers, “A Death Penalty Puzzle,” Washington Post, June 30, 2008) (emphasis added). See Deterrence and Supreme Court.