Efficacy Data

For our efficacy survey data, we referenced the following 2008 study (following up its 1996 predecessor):

RECENT DEVELOPMENTS | DO EXECUTIONS LOWER HOMICIDE RATES?: THE VIEWS OF LEADING CRIMINOLOGISTS* MICHAEL L. RADELET** & TRACI L. LACOCK***

Here's a hyperlink to the PDF of the study: https://files.deathpenaltyinfo.org/legacy/files/DeterrenceStudy2009.pdf

Abstract of the Survey Study (1996 and 2008)

"The question of whether the death penalty is a more effective deterrent than long-term imprisonment has been debated for decades or longer by scholars, policy makers, and the general public. In this Article we report results from a survey of the world’s leading criminologists that asked their expert opinions on whether the empirical research supports the contention that the death penalty is a superior deterrent. The findings demonstrate an overwhelming consensus among these criminologists that the empirical research conducted on the deterrence question strongly supports the conclusion that the death penalty does not add deterrent effects to those already achieved by long imprisonment."

For our purposes of better understanding the narrative of moving away from the death penalty, we decided to visualize the result tables generated from these surveys. The following is what we came up with.

Notes on Efficacy Survey Data

The following points are in regards to the prior plots and what could be determined from them.

Both 1996 and 2008 surveys of expert opinions indicate that support for the death penalty has waned significantly since the 70s.
May be reasonable to presume that most people seem understand homicide rates to be independent from death penalty’s existence, subsequently meaning it is not effective in deterring murders amongst other capital crimes.
Some 2008 surveys indicate more differing opinions?
- Could be a benefactor of slightly larger samples used and or external trends (ie. increased political polarization/radicalization over time)