The NYT notes the new controversy involves studies done over the past decade primarily by economists showing a significant deterrence and studies primarily in law journals debating that. While it may seem odd for an economist to study the death penalty the models for measuring an effect are based on economics - "To economists, it is obvious that if the cost of an activity rises, the amount of the activity will drop." Lawyers point out that while the studies seem broad, one looked at 3054 counties over 20 years, the actuality is that there are only a few death cases and executions, in 2003 there were 153 death penalties and 65 executions, about one in 300 homicides results in a death penalty so the chances of receiving one for a murder are rather slim.
The economist's models attempted to account for varying crime rates, conviction rates and other factors and came up with murders declining as executions climbed. Various studies have indicated between 3 and 18 lives saved per execution. However,
“Deterrence cannot be achieved with a half-hearted execution program,” Professor Shepherd of Emory wrote in the Michigan Law Review in 2005. She found a deterrent effect in only those states that executed at least nine people between 1977 and 1996.The facts surrounding prison life may have more of a deterrent effect,
A 2003 paper by Lawrence Katz, Steven D. Levitt and Ellen Shustorovich published in The American Law and Economics Review found a “a strong and robust negative relationship” between prison conditions, as measured by the number of deaths in prison from any cause, and the crime rate. The effect is, the authors say, “quite large: 30-100 violent crimes and a similar number or property crimes” were deterred per prison death.The math doesn't seem to be quite as clear as it does at first blush, questions remain as to whether murders are actually capable of making those rational calculations, and worse considering the solution rate for murder and then the number of death penalties imposed if the calculation might fall on the side of murder. When things like criminal thinking errors (I'll never get caught), obsessions, passions, greed, and a host of other mental malfunctions get tossed into the mix one really has to wonder if fear of execution has much to do with anything.
Some folks like to do the trade game of one life, the executed, for many and in terms of a dead murderer saving several lives it seems almost reasonable. There is the little matter of the state killing a helpless human being after having them contemplate that idea for some extended period of time. There is to me not only the wrongness of the act, but the worse attribute of the responsibility being spread amongst all the citizens who are so divorced from the actual deed. There is the final horror of the whole thing, humans and their systems are not infallible, some innocents will be in the mix and once you have been a part of that, you are not one iota different from the most cold blooded of killers, considering all that goes with an execution.
This nation should be able to come up with a workable alternative to capital punishment, but .then there are a lot of things we really ought to be able to come up with...