This paper aims to contribute to give an answer to the question raised in the controversy on the abolition of capital punishment in South Korea by introducing recent American law and economy theories on the subject. Arguments of the both sides of abolitionists and proponents of death penalty in Korea have been so far based on the so-called “legal emotion” and any scientific theory has never been contructed with a view to objectify the problem. In American academic society, economic approach to the impact of the capital punishment in the perspective of deterrent effect has a considerably long history since the article Isaac Ehrlich published in 1975. Many similar studies have been thereafter published to endorse the Ehrlich thesis. However, it is pointed out by John J. Donohue, III and Justin Wolfers in their very recent work (2009) that these studies show very crucial theoretical defects when they try to prove the deterrent effect of death penalty. By summarizing the history of econometric debate on the question, Donohue and Wolfers argue that OLS estimates studies show no statistically significant evidence of deterrence, which is contrary to what one easily expects from such studies. We can conclude therefore that from the econometric viewpoint, death penalty has no deterrent effect on homicide crimes.