I think the issue of migration to cities is serious, but I think more telling is the issue developed countries are having with immigration. I think that is a symptom of overpopulation in the same sense that Harrison sees it. In many countries there are more people than there are resources to provide for them well. This is even becoming an issue in the U.S. While some economists point to an ever-rising stock market, others point to the growing disequilibrium between different sectors of society. The people in the U.S. for the most part enjoy a good standard of living, but it is a standard premised on debt. When will the bill come due? How will paying that bill affect quality of life in the U.S? How fast will those effects become manifest?

All open questions and none of them give me comfort.