THE TRUE VALUE OF LAMBDA WOULD APPEAR TO BE ZERO: AN ESSAY ON CAREER CRIMINALS,CRIMINAL CAREERS,SELECTIVE INCAPACITATION,COHORT STUDIES,AND RELATED TOPICS*

The idea of selective incapacitation and the distinction between prevalence and incidence (participation and lambda) justify the search for a group of offenders whose criminality does not decline with age and who may be identified solely on the basis of legally relevant variables. This paper questions such research, arguing that the decline in age with crime characterizes even the most active offenders. and that the distinction between incidence and prevalence does not deserve the theoretical, research, or policy attention it has been claimed to merit (Farrington, 1985; Blumstein and Graddy, 1981–1982). In doing so, it relies on research results widely accepted in criminology. Thus, the current focus of criminological research on the “career criminal,” on selective incapacitation, and on longitudinal research remains unjustified.