The value of a statistical life is an important concept in health and environmental economics. This paper provides definitions of the value of a statistical life, and considers single-period and life cycle models. It shows how the value of a statistical life can be measured simply in empirical studies, and addresses the important age profile issue. Available empirical evidence is briefly presented, and recent studies are included that use meta-analysis to determine which variables are appropriate to explain the variance of estimates of the value of statistical life.