Population Growth

Posner comments on his blog:

A neglected negative effect of population growth is on political governance. There seem to be strong diseconomies of scale in government. Increases in population, and concomitant increases in economic activity, crime, demand for medical services, and so forth make the job of government more difficult. What seems to be an incipient crisis of competence in the U.S. government may be at least distantly related to the doubling of the U.S. population since 1948.

Then again, medicine has a negative effect on disease.