In the developing world, most people don't yet live in big well-run cities. Given the chance to move to one, hundreds of millions of people would go there to get a job, get an education for their children, and live in a place that is clean, safe, and healthy.

In the developing world, most people don't yet live in big well-run cities. Given the chance to move to one, hundreds of millions of people would go there to get a job, get an education for their children, and live in a place that is clean, safe, and healthy.

It is the job of government to prevent a tragedy of the commons. That includes the commons of shared values and norms on which democracy depends.

After 1960, anyone who wanted to discuss almost any aspect of U.S. public policy - from how to make cars safer to whether to abolish the draft, from how to support the housing market to whether to regulate the financial sector - had to speak economics.