Results conclude from existing cost-benefit analysis (CBA) evidence that while prison may be an efficient sentencing option for more serious offenders, for non-serious offenders the cost outweighs the benefit of the incapacitation, rehabilitation, and specific deterrence effects. Findings suggest that prison is an inefficient sentencing option, but where the analysis differentiates between offender types, findings suggest that prison may be efficient for more serious offenders. The theoretical models developed by economists suggest that whether severity of punishment impacts on offending is dependent upon the individuals' attitudes towards risk. Given that the decision to incarcerate offenders is related to the severity of punishment, the literature would suggest that the deterrence effect of prison is equivocal and depends on the degree to which the relevant population is risk averse. The review identified only one economic study that related to the final effect of prison: retribution. More CBA is required to determine the relative efficiency of types and lengths of sentences for different offenders in the United Kingdom; econometric analysis is required to determine whether prison is likely to have a general deterrent effect in the United Kingdom. Finally, while very little is known about the retributive effect of prison, it is reasonable to conclude that using prison for anyone but those convicted of serious offenses is a waste of public resources. Notes and references