Ruchir Sharma again used a New York Times column to complain about plans put forward by Elizabeth Warren and Donald Trump (more the former than the latter) to lower the value of the dollar to make U.S. goods and services more competitive in the world economy. While he raises a number of geopolitical arguments, the gist of his economic argument is that the U.S. is able to run large and persistent trade deficits because the dollar is the leading reserve currency in the world. (Hence the "exorbitant privilege.")

This ability to run large trade deficits could be a good thing, if we had an economy that was generally near full employment. In that case, the deficit on trade allows us to consume and invest more than would otherwise be possible. However, few serious economists would argue that we have been at or near full employment in the last decade.

Many, if not most, mainstream economists have embraced the idea of "secular stagnation." This is a more complicated way of saying insufficient demand. In other words, the U.S. economy has not been at or near full employment for the last decade because it has not had enough demand.

A big part of the "not enough demand" story is the trade deficit. If we had balanced trade instead of a deficit of 3.0 percent of GDP, it would have roughly the same impact on aggregate demand as a $600 billion annual stimulus program, all of it in the form of government spending. In other words, the "exorbitant privilege" has been the privilege of having an economy that has been operating well below full employment, with lots of excess capacity.

But wait, there's more. Because manufacturing goods account for the overwhelming majority of traded items, the large trade deficit translates into a loss of millions of manufacturing jobs. Since manufacturing jobs have historically been a source of relatively high-paying employment for workers without college degrees, the trade deficit has been a big factor in the rise in inequality, especially in the last two decades as the over-valued dollar caused it to explode.

So, "exorbitant privilege" translates into secular stagnation and increased inequality. And Elizabeth Warren wants to jeopardize this with her plans to lower the value of the dollar.