Capital punishment and deterrence: a comment on Cloninger's paper

Cloninger (1992) applied the portfolio approach to criminal behaviour and illustrated the deterrent effect of capital punishment by use of data from 1983-1988 across the states of America and the District of Columbia. This comment suggests two possible flaws in Cloninger's analyses, which, if taken into account, may shed more light on the effect which he purports to demonstrate and it suggests that application of the analyses to an earlier historical period may be necessary.