The Federal Reserve is poised to raise interest rates Wednesday for the first time in 9½ years.
It may not take so long to know whether its decision was correct.
History is filled with cases, from the Fed in the 1930s to the European Central Bank in 2011, when central banks raised rates prematurely, sometimes with dire consequences. Raising rates or otherwise tightening credit too soon can slow borrowing, jolt confidence and choke growth.
When the global financial system started buckling in 2007, central banks cut rates to fight the worst economic catastrophe since the 1930s. As the crisis escalated in late 2008, many rates were slashed to record lows. The Fed cut its benchmark rate to near zero.