Economics is at its best when making the counter-intuitive seem obvious. For example, Paul Krugman explaining China and the liquidity trap:
Right now we’re in a liquidity trap, which, as I explained in an earlier post, means that we have an incipient excess supply of savings even at a zero interest rate. …
In this situation, America has too large a supply of desired savings. If the Chinese spend more and save less, that’s a good thing from our point of view. To put it another way, we’re facing a global paradox of thrift, and everyone wishes everyone else would save less.
Or to put it a third way, the argument that a reduction in China’s dollar purchases would be contractionary for America because it would drive up interest rates is equivalent to the argument that fiscal expansion is contractionary for the same reason — and equivalently wrong.
But what if China doesn’t spend more, but just reallocates its reserves from dollars to, say, euros? The answer is, that’s also good for us: a weaker dollar will help our exports, at Europe’s expense.