Deterrence

Deterrence Definition

Deterrence — literally “putting off” or “discouraging” — is the constraint of a rational actor by raising the expected penalty for an unwanted action. In criminology it refers to discouraging crime through the threat of being caught and punished; in political sociology and international relations it denotes the capacity to protect oneself from attack by threatening an adversary with retaliation perceived as unacceptable — as when a state raises defence spending or mobilises forces on a contested border.

Deterrence and Prevention

Deterrent and preventive measures overlap, since both aim to discourage certain acts by restricting the rational choices of others: the threat of imprisonment and the threat of nuclear escalation are both held to prevent, respectively, crime and nuclear war. In criminal justice, the prospect of arrest, trial, conviction, and punishment is treated as a general deterrent, and deterrence is invoked as a justification for punishment itself. Imprisonment is assumed to deter powerfully, but its effectiveness is disputed — and although prison also aims to reform, recidivism remains high in most modern penal systems.

Deterrence Theory

The theory descends from the early utilitarians Cesare Beccaria and Jeremy Bentham: people commit crimes to the extent that the pleasure outweighs the pain, so certain, severe, and swift legal punishment raises the cost and can deter. Neither founder defined deterrence systematically; the conventional definition is Gibbs’s (1975) — the omission or curtailment of a crime from fear of legal punishment. “Omission” and “curtailment” mark two possibilities: refraining from the crime entirely, or merely restricting it (a motorist may speed only occasionally, believing that habitual speeding will eventually bring a fine).

Core Propositions

Though no single version of the theory commands universal acceptance, all include some form of the central claim: the greater the certainty (likelihood), severity (magnitude), and celerity (swiftness) of legal punishment for a type of crime, the lower the rate of that crime. Certainty has long been considered a more effective deterrent than severity or celerity, and has been the principal variable in research. Punishments can be considered objectively — for example, estimating the certainty of imprisonment from the ratio of persons imprisoned to crimes committed, and severity from average time served — or perceptually, by asking people how certain and severe they believe punishment to be. This yields three linked propositions: objective punishment levels should reduce crime rates; objective levels should raise perceived levels; and perceived levels should reduce crime rates.

Evidence

Before 1980 most research examined the objective proposition — Gibbs (1968), for instance, found a negative association across US states between the objective certainty and severity of imprisonment for homicide and the homicide rate. The assumed link between objective and perceived punishment, however, has fared poorly: Erickson and Gibbs (1978) found only a moderate association between objective and perceived certainty of arrest across ten crime types, and no support for the implication that objective certainty affects crime through perception. Research has therefore shifted to the perceptual proposition, which best captures the element of fear integral to deterrence. Scores of studies find that perceptions of the certainty of punishment bear negative, deterrent-like associations with offending; perceived severity shows such effects only when individual assessments of sanction costs are taken into account (Nagin 1998).

Extralegal Punishments

Crime rates also respond to threats of extralegal punishment — stigma, divorce, job loss — which complicates the theory in at least three ways: legal and extralegal punishments may affect crime independently; legal punishment may work through extralegal consequences (fear of losing one’s job if arrested); and the two may interact, with legal threats deterring only those who also expect an extralegal penalty.