A theory of participation in illegitimate activities is developed and tested against data on variations in index crimes across states in the United States. Theorems and behavioral implications are derived using the state preference approach to behavior under uncertainty. The investigation deals directly with the interaction between offense and defense: crime and collective law enforcement. It indicates the existence of a deterrent effect of law-enforcement activity on all crimes and a strong positive correlation between income inequality and crimes against property. The empirical results also provide some tentative estimates of the effectiveness of law enforcement in reducing crime and the resulting social losses.

We specify a demand function for longevity, or "quantity of life," along with corresponding demand functions for indicators of "quality of life" and a value-of-health and life extension function. We show that the demand for health must be derived in conjunction with that for longevity and the related consumption plan, and that all choices depend on initial individual endowments and terminal conditions. Our comparative dynamics predictions indicate that optimal health and longevity are increasing functions of endowed wealth rather than, necessarily, current income; that improvements in opportunities to produce health can accentuate the differences between endowed health and attained longevity levels; and that the value individuals ascribe to their health may be increasing over a good portion of their life cycle. We use this model to analyze observed empirical variations in levels and trends of life expectancy and in exposure to health risks across different population groups.

We develop an overlapping-generations model of endogenous growth in which human capital is the engine of growth and the generations are linked through material and emotional interdependencies within the family. Parents invest in their children to achieve both old-age support (care) and emotional gratification, and material support from children is determined through self-enforcing implicit contracts. We show that optimal intergenerational trade can then lead to maximization of growth opportunities. Our model produces a theory of the "demographic transition" linking longevity, fertility, and economic growth. We also show that while population aging may raise the growth rate, an increase in young-age longevity is likely to produce a greater increase in the growth rate and a reduction in the fertility rate in a growth equilibrium. These predictions and the model's implications concerning the behavior of private savings during the takeoff period appear consistent with empirical evidence.

This paper reexamines the issues of compliance with and enforcement of the minimum wage law recently addressed in this Journal by Ashenfelter and Smith and by Grenier. Pursuing a more rigorous methodology we are able to add new general conclusions, and correct and reconcile some previous conflicting conclusions concerning the role of the disparity between the minimum and free market wages, the level and elasticity of labor demand, and the magnitude of deterring monetary sanctions on the noncompliance decision. Our formulation also addresses the law evasion (reduced wages) as well as the law avoidance (modified employment) aspects of the noncompliance decision, which previous formulations have ignored.