The major hypothesis is that the level of crime is a function of the probability of arrest, the cost to the offender of arrests, the probability of conviction given arrest, the cost to the offender of conviction net of arrest cost, the probability of incarceration given conviction and the cost to the offender of incarceration net of conviction costs. The crime rate is also hypothesized to be a function of the variables which affect legal and illegal wage rates. The results indicate that the threat of punishment does deter individuals in New York State from committing crimes. The probability of arest is found to have a highly significant negative effect on all offense and on property-related offenses, holding other variables constant. However, none of the law enforcement variables have significant effects on crime in the case of violent offenses. The cost to the offender of arrest and the cost to the offender of conviction net of arrest costs are found to deter offenders from committing property-related crimes and all offenses. The elasticity of the crime rate with respect to these three variables is found to range about -.20 and -.45. The cost to the offender of arrest and the cost to the offender of conviction net of arrest costs cannot be made. The evidence suggests that significant differences in the deterrent effectiveness of different policies may exist. Chapter footnotes and tables are included throughout. A bibliography (about 21 references) is appended.