Deterrence or encouragement

One reason it's tough to identify deterrence effects of the death penalty: the long and variable lags between sentence and execution can be under conditions more pleasant than those in the general prison population.

AS AN ORANGE COUNTY jury debated in 2009 whether the white supremacist Billy Joe Johnson should live or die for murdering a fellow gang member, he asked to be sent to death row. Not because he felt any sudden remorse for the five people he’d killed over the years—“I commit crimes when people piss me off,” he once explained, matter-of-factly—but because Johnson believed he’d have better living conditions, including liberal phone privileges, a bigger cell, and daily human interaction, at San Quentin’s death row than he would at Pelican Bay, one of the state’s toughest maximum-security prisons, where he was serving a 46-year-to-life sentence, primarily in solitary confinement.

He also knew that the odds were good that he might never be executed. Bogged down by constitutional challenges and appeals, California’s system takes an average of 20 years to move a prisoner from conviction to execution.

Experts on both sides of the death-penalty debate have long agreed that California’s system is the nation’s costliest and least efficient. This June, a landmark report by Paula M. Mitchell, a professor at Loyola Law School, and Arthur L. Alarcón, a senior judge on the Ninth Circuit Court of Appeals, unearthed new data that reveal just how bad the system is.

Their report showed that since the current death-penalty statute was enacted in 1978, taxpayers have spent more than $4 billion on only 13 executions, or roughly $308 million per execution. As of 2009, prosecuting death-penalty cases cost upwards of $184 million more each year than life-without-parole cases. Housing, health care, and legal representation for California’s current death-row population of 714—the largest in the country—account for $144 million in annual extra costs. If juries continue to send an average of 20 convicts to San Quentin’s death row each year, and executions continue at the present rate, by 2030 the ranks of the condemned will have swelled to more than 1,000, and California’s taxpayers will have spent $9 billion to execute a total of 23 inmates.

I'd want to see that as a per-case excess cost rather than as an aggregate. But it's hard to see how the system makes sense.