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

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

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.

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.

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

Human capital analysis starts with the assumption that individuals decide on their education, training, medical care, and other additions to knowledge and health by weighing the benefits and costs. Benefits include cultural and other non-monetary gains along with improvement in earnings and occupations, while costs usually depend mainly on the foregone value of the time spent on these investments.

Economy is the art of making the most of life.