CEPR, London

The harm caused by many acts is not certain but probabilistic. Cur-rent public enforcement of the law combines harm-based sanctions (usu-ally in criminal law) with act-based sanctions (very common in adminis-trative law and regulation). We propose an economic theory of the choice between harm-based and act-based sanctions in public enforcement. The efficiency of act-based versus harm-based sanctions is analyzed and a ty-pology of the determinants is drawn up. Legal policy implications are discussed. JEL Classification: K4