Existentially speaking, are you a Stomach or a Brain?

Alex Tabarrok says:

People used to think that more population was bad for growth. In this view, people are stomachs--they eat, leaving less for everyone else. But once we realize the importance of ideas in the economy, people become brains--they innovate, creating more for everyone else.

New ideas mean more growth, and even small changes in economic growth rates produce large economic and social benefits. At current income levels, with an inflation-adjusted growth rate of 3% per year, America's real per capita gross domestic product would exceed $1 million per year in just over 100 years, more than 22 times higher than it is today. Growth like that could solve many problems.