One of the most common questions I get about my research on systematically biased beliefs about economics is: Yes, but why do people have these biases? Why do people underestimate the social benefits of the market? Why are they particularly unreasonable about international and labor markets? And why do they think the economy is bad and getting worse?

I’ve got a few answers of my own, but the scholar hardest at work on these questions is Paul Rubin. He had an interesting piece on this topic a couple years ago in the Southern Economic Journal. And Monday, amazingly enough, the Washington Post published his op-ed on this very topic. (HT: Mankiw).

Here’s Rubin on the origin of anti-market bias:

Our primitive ancestors lived in a world that was essentially static; there was little societal or technological change from one generation to the next. This meant that our ancestors lived in a world that was zero sum — if a particular gain happened to one group of humans, it came at the expense of another.

This is the world our minds evolved to understand. To this day, we often see the gain of some people and assume it has come at the expense of others.

Here’s Rubin on anti-foreign bias:

[O]ur evolutionary intuition is that, because foreign workers gain from trade and immigrant workers gain from joining the U.S. economy, native-born workers must lose. This zero-sum thinking leads us to see trade and immigration as conflict (“trade wars,” “immigrant invaders”) when trade and immigration actually produce cooperation and mutual benefit, the exact opposite of conflict.

I’ll share my thoughts in a future post. But first, I’m curious to hear readers’ reaction to Rubin’s story. What do you think?