DEATH PENALTY'S DEADLY VACATION

THE Supreme Court on Tuesday effectively halted U.S. executions via lethal injection until it can rule on a challenge to the constitutionality of a particu lar execution "cocktail."

This is just the latest example of the whittling away of the death penalty - the courts have already cut executions by over a third since 1999. But this latest suspension of executions is likely to demonstrate yet again that the death penalty deters crime.

The most recent Gallup poll shows that 69 percent of Americans favor the death penalty, yet opponents continue to force a widespread public debate over its effectiveness.

A common claim is that executions - now down to about 60 per year - are too rare to deter criminals. To see the spuriousness of this complaint, consider that "only" about 55 police officers are killed each year - yet we (academics and the public alike) still see it as a dangerous job, one whose stresses help account for higher divorce and suicide rates.

Yet those killings are spread across about 700,000 U.S. police officers. By contrast, 2005 saw 60 executions and 16,700 murders - that is, we executed murderers at 45 times the rate at which criminals killed police officers. Given the impact on police, how can we believe that murderers would be unaffected by the much larger risk they face? Critics also point to mistaken convictions - yet they still can't point to a single case in which an innocent person was executed. This is ultimate proof that our justice system works well - making due account, for example, for the fact that witnesses sometimes make misidentifications.

Others, like the American Bar Association, claim racial biases in how the death penalty is applied. In fact, while African-Americans have committed 53 percent of all murders since 1980 in which the killer's race is known, they have accounted for only 38 percent of the executions.

The campaign against the death penalty also gives us such spurious studies as a much-publicized look by The New York Times that compared murder rates in 1998 in states with and without the death penalty.

The Times concluded that capital punishment was ineffective in reducing crime, noting that "10 of the 12 states without capital punishment have homicide rates below the national average . . . while half the states with the death penalty have homicide rates above the national average."

In fact, the 12 states without the death penalty have long enjoyed relatively low murder rates - unrelated to capital punishment. When the death penalty was suspended nationwide from 1968 to 1976, the murder rate in these states was still lower than in most others.

What's much more important is that the states that reinstituted the death penalty after 1976 collectively saw a significantly bigger drop in murder rates (about 38 percent larger than in the 12 no-execution states) by 1998. Without executions, murder rates skyrocketed from 1968-76. Studies that sought to pin the '70s rise in violent crime to other factors were generally inconclusive.

Studies of the period since the death penalty's return have shown its effectiveness. Generally, the studies over the last decade that examined how the murder rate in each state changed as the states changed their execution rates found that each execution saved the lives of roughly 15 to 18 potential murder victims. (About 75 percent of studies by economists find that more executions reduce murder. Overall, the rise in executions during the '90s accounts for about 12 to 14 percent of the overall drop in murders.)

Will the Supreme Court insist on forcing us to re-learn this awful lesson, by limiting the use of lethal injections? With the U.S. murder rate now rising slightly, the court would be wiser to reconsider all the restrictions that it has already imposed on the death penalty.

The Constitution explicitly recognizes the validity of the death penalty in four distinct passages; it is hard to see how the court could strike it down as unconstitutional. But too many lives are at stake for the courts to once again stop executions.

*John Lott is a senior research scientist at the University of Maryland; his latest book is "Freedomnomics."