AMERICA’S experiment with quantitative easing – and the ensuing quantitative tightening – is almost over.

This week, the US Federal Reserve will likely announce plans to slow the shrinkage of its balance sheet. This foreshadows the end of a long period in which it sought to stimulate the economy by holding large quantities of Treasury and mortgage securities, and later had to shrink its balance sheet.

So did it work? Yes, but at excessive cost.