Dallas – Since 1993, every category of violent crime has decreased. The reason: The likelihood of going to prison has jumped significantly.
"We have increased the odds of incarceration," said Dr. Morgan Reynolds, director of the National Center for Policy Analysis' Criminal Justice Center and author of the just-released study Crime and Punishment in America 1998. "Perpetrators know it is more costly to commit crime, and that acts as a deterrent."
According to findings of the Dallas-based public policy research institute:
- Murder has dropped 30 percent as the probability of going to prison for murder has risen 53 percent.
- Robbery has dropped 29 percent as the probability of imprisonment has risen 28 percent.
- Aggravated assault has decreased 14 percent as the probability of imprisonment has increased 27 percent.
"The best measure of the potential cost of committing a crime is 'expected punishment,'" said Dr. Reynolds. Expected punishment equals the number of days in prison a criminal can expect to serve for committing a crime. It is calculated by applying the probabilities of being apprehended, prosecuted, convicted and sentenced to the average sentence for each crime.
The expected costs to a prospective criminal today are significantly greater than they were in 1980 for every category of serious crime, he said. For example, between 1980 and 1996:
- Expected punishment for murder more than doubled;
- Expected punishment for rape tripled;
- Expected punishment for burglary doubled;
- Expected punishment for larceny/theft and auto theft nearly doubled.
The study points to two of the most populous states as examples of the crime and punishment cause-and-effect. During the 1980s, California increased its prison population at a rate faster than the nation and experienced a decline in serious crime compared to the nation as a whole. Texas, meanwhile, experienced a lag in its prison population growth and its rate of serious crime shot up. During the 1990s, those trends have reversed in both states.
"All the evidence shows that potential criminals respond to incentives," said Dr. Reynolds. "Crime increases when the expected punishment decreases, and crime decreases when the expected punishment increases."