America's economy is slipping to number two. Don't panic.

In fact, the link between the absolute size of your economy and pretty much any measure that truly matters is incredibly weak. Whenever China takes over the top spot, it will still lag far behind the world’s leading countries on indicators reflecting quality of life. For starters, there are a lot more people sharing China’s GDP; even the rosiest forecasts for the country’s economic growth suggest that per capita income will be lower than in the United States for decades to come. The average American lives five years longer than the average person in China, and civil and political rights in the world’s soon-to-be-biggest economy are routinely abused. Living in an America that ranks second in GDP to China will still be far, far better than living in China.

There are some real economic costs related to losing the top spot in the GDP rankings, but they are small and manageable. The dollar might lose its dominance as the currency of choice for central bank reserves and trading, and some predict that will increase the cost of U.S. borrowing and exporting. In fact, the dollar share of global reserves has already fallen from about 80 percent in the 1970s to about 40 percent today, with the euro and the renminbi gaining ground, but there isn’t much sign that that has spooked global markets. Meanwhile, businesses in the rest of the world still manage to export, even though they must go through the trouble of exchanging currencies.

And if you want further reassurance that you don’t need to be large to be rich, remember that in tiny Luxembourg, average incomes are almost twice those in the United States.