1. There is no evidence to support the claim that capital punishment deters murder.
2. Studies have consistently shown that states without the death penalty have lower murder rates than those with it.
3. More sophisticated statistical methods have been used to analyze data, but the results still show no increased deterrence due to the death penalty.
The article "Does Capital Punishment Deter Murder?" by John Lamperti provides a comprehensive analysis of the evidence for and against the deterrent effect of capital punishment on murder rates. The author acknowledges that ethical, philosophical, and religious values are central to the debate over capital punishment but argues that factual evidence should inform policymaking. The article focuses on deterrence as the only major pragmatic argument in favor of the death penalty.
The author begins by defining the question correctly, which is whether capital punishment provides a better deterrent to murder than long imprisonment. He notes that many things affect homicide rates, making it difficult to separate the impact of capital punishment from other variables. The author cites several studies that failed to reveal any additional deterrent effect due to capital punishment, including comparisons between states with and without the death penalty and studies of short-term deterrence.
The author also discusses regression models used by researchers such as Ehrlich, who claimed to have found evidence for deterrence. However, Lamperti points out flaws in Ehrlich's methodology and notes that subsequent research has failed to replicate his findings.
Overall, Lamperti concludes that there is no alternative but to conclude that capital punishment cannot be justified on the basis of its deterrent effect. While he acknowledges that statistical analysis is essential for interpreting complex data and making decisions in the face of uncertainty, he also notes that interpretation can be difficult and subject to bias.
One potential bias in this article is its focus solely on deterrence as a pragmatic argument in favor of capital punishment. It does not consider other arguments such as retribution or incapacitation. Additionally, while Lamperti acknowledges ethical, philosophical, and religious values as central to the debate over capital punishment, he does not explore these values in depth or consider how they might influence policymakers' decisions.
Another potential bias is the author's own position on capital punishment. As a professor emeritus of mathematics rather than a criminologist or legal expert, Lamperti may not have the same level of expertise in this area as other scholars. Additionally, while he cites numerous studies that failed to find evidence for deterrence, he does not explore counterarguments or potential flaws in these studies.
Overall, while Lamperti's article provides a thorough analysis of the evidence for and against the deterrent effect of capital punishment on murder rates, it is important to consider potential biases and limitations in his analysis. Policymakers should consider a range of arguments and evidence when making decisions about capital punishment rather than relying solely on one pragmatic argument.