The Great Enrichment of the past two centuries has one primary source: the liberation of ordinary people to pursue their dreams of economic betterment.
Why are we so rich? An American earns, on average, $130 a day, which puts the U.S. in the highest rank of the league table. China sits at $20 a day (in real, purchasing-power adjusted income) and India at $10, even after their emergence in recent decades from a crippling socialism of $1 a day. After a few more generations of economic betterment, tested in trade, they will be rich, too.
Actually, the “we” of comparative enrichment includes most countries nowadays, with sad exceptions. Two centuries ago, the average world income per human (in present-day prices) was about $3 a day. It had been so since we lived in caves. Now it is $33 a day—which is Brazil’s current level and the level of the U.S. in 1940. Over the past 200 years, the average real income per person—including even such present-day tragedies as Chad and North Korea—has grown by a factor of 10. It is stunning. In countries that adopted trade and economic betterment wholeheartedly, like Japan, Sweden and the U.S., it is more like a factor of 30—even more stunning.