Although public executions temporarily deter potential murderers, homicide rates soon return to their usual--or even higher--levels, two recent studies have shown.
David P. Phillips '64, associate professor of sociology at the University of California-San Diego, said Thursday his research indicates that public executions deter killers for two weeks. Afterwards, the homicide rate begins to rise again.
"Within five weeks, the drop has been cancelled out," Phillips said.
Glenn L. Pierce, assistant director of Northeastern University's Center for Applied Social Research, said Thrusday, "At a minimum, capital punishment has no effect, and at most it has a brutalizing effect, which encourages two or three additional homicides in the month after an execution."
Pierce and William J. Bowers studied the effect of the 695 executions in New York between 1907 and 1963. They analyzed the effect of publicity about executions in a given month on the homicide rate during the following month.
The two studies are not necessarily contradictory because they examine the different cricumstances, Pierce said. "Whatever the effect of executions is, the one thing that's clear is it's not much," he said.
The Northeastern study found an increase of 600 murders out of a total of 28,800 in a 58-year period.
The University of California study determined that the net effect of capital punishment was zero.
Pierce critized Phillips for labeling his results a "deterrent effect," rather than a delay. "Were he able to look at more than the initial decline, he would have found that it was followed by a larger increase, which is what we're seeing," Pierce said.
But Phillips said any study which uses monthly date, such as Northeastern's, would be "considerably blurred." He added, "It's really curious that they (Pierce and Bowers) examined the month after the execution,' instead of the month of the execution.
Phillips used weekly date to study the effect of 22 highly publicized executions in London between 1858 and 1921. "There is not way to know whether the pattern I found holds for any other place or time," he said.
James Q. Wilson, Shattuck Professor of Government, said Friday that although Phillips correctly used the word "deterrent," he could not tell if the results were significant because "the numbers he's talking about are very small."
"I don't think that Phillips' study is going to cause anyone to change his mind or lead to any new conclusions," Wilson said. He added that public policy decisions on capital punishment should be based on moral considerations.
Wilson said the questions is not whether capital punishment is a deterrent, but whether it is effective when used rarely.
Each study is based on opposing views of how potential murderers react to executions. Pierce and Bowers found that "the publicity surrounding an execution, let alone witnessing one, may cause some pepole--perhaps those on the fringe of sanity--to become fascinated and obsessed with the condemned person's crime, even to the point of imitating it."
However, Phillips said the most plausible explanation for his results is that "public executions temporarily deter homicides which then reappear after the lesson of the execution fades from memory."
Wilson said, "We have no way of knowing which assumption is right," although laboratory evidence indicates that observers tend to identify with the person being punished.
The Northeastern study will be published next week in the Journal of Crime and Delinquency. The University of California research is in the current issue of the American Journal of Sociology.