There's a new and surprising complication in the increasingly complicated debate over the death penalty: Pardons kill.
At least that's the implication of a recent study by H. Naci Mocan, chairman of the economics department at the University of Colorado at Denver. His analysis of death sentences and state homicide rates suggests that pardoning convicted killers leads to an increase in murders.
Mocan also found that the murder rate fell as executions increased--a finding certain to be embraced by those who argue that the death penalty serves as a deterrent to murder. It's also just as certain to be scrutinized by death penalty opponents.
The pardon effect is actually a matter of simple market economics, asserts Mocan, who is also a research associate at the National Bureau of Economic Research in Cambridge, Mass. Mocan's explanation: Pardons reduce the chances that convicted killers will pay the ultimate price for committing murder. Thus, he says, a pardon "represents a decrease in the cost of committing the crime," and as his study shows, is accompanied by an increase in the homicide rate. Conversely, if you increase the "cost" of committing murder by executing a larger share of convicted killers, then economic theory suggests the murder rate will fall, Mocan said.
Mocan and graduate student R. Kaj Gittings analyzed data collected by the Justice Department on all 6,143 death sentences handed out between 1977 and 1997 in the United States. During that time, 432 convicted killers were executed while 123 were pardoned, either through a grant of clemency or a commutation of their sentence.
The researchers combined this data with detailed information from each state where the murders occurred. Those variables included the state's per capita income, unemployment rate, percentage of young adults in the population, racial composition, infant mortality rate, proportion of residents who live in large cities and even per capita alcohol consumption--all factors known to be associated with homicide rates.
They concluded that each execution "decreases [the number of] homicides by five to six, while three additional pardons generate 1 to 1.5 additional homicides" beyond the number of murders that would have been expected to occur in the state during the following year. Their findings appear in a NBER working paper published in December.
Mocan suspects some potential killers approach their crimes in much the same way that the average consumer approaches a major purchase: Ultimately, both the buyer and the killer base their final decision on available information.
"Executions make headlines, and pardons make headlines as well," he said. "The question is whether the headlines in the media and other informal channels are powerful enough to affect behavior. The answer is evidently yes, because that is exactly what we are finding."
Mocan realizes proponents of capital punishment will seize upon the study to buttress their case for legal executions. The idea of his study being used in that manner gives him pause.
"There are still a number of unresolved issues regarding imposition of the death penalty," he said. In his paper, he notes that racial and gender disparities in sentencing for capital crimes raise troublesome questions about capital punishment.
Does he personally support the death penalty? The question clearly makes Mocan uncomfortable.
"I do believe that the death penalty is a deterrent," he answered, choosing his words with care. "But I cannot really say I am in favor of the death penalty because of all these issues, from questions of discrimination to fundamental ethical issues surrounding the death penalty."