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.

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.

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.

A stronger yuan could lead to greater Chinese asset accumulation in the U.S. and elsewhere.

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.