Different constraints are decisive for different situations, but the most fundamental constraint is limited time.

Still, intuitive assumptions about behavior is only the starting point of systematic analysis, for alone they do not yield many interesting implications.

I argued last year on my shared blog that selling the right to immigrate would be the best approach to legal immigration. Among other benefits, the revenue from immigrants' payments could reduce taxes. Paying for the right to immigrate would also negate the argument that immigrants get a free ride when they gain health care and other benefits. Moreover, making immigrants pay would attract the type of immigrants who came much earlier in American history: young men and women who are reasonably skilled and want to make a long-term commitment to the United States.

Different constraints are decisive for different situations, but the most fundamental constraint is limited time.

Why in almost all societies have married women specialized in bearing and rearing children and in certain agricultural activities, whereas married men have done most of the fighting and market work?

The Treatise tries to analyze not only modern Western families, but also those in other cultures and the changes in family structure during the past several centuries.

My work on human capital began with an effort to calculate both private and social rates of return to men, women, blacks, and other groups from investments in different levels of education.