A weaker currency, once the cure-all for ailing economies around the world, isn’t the panacea it once was. Just look at Japan, where the yen plunged 28 percent in the two years through 2014, yet net exports to America still fell by 10 percent in the span. Or at the U.K., where the pound’s 19 percent tumble in the two years through 2009 couldn’t stave off a 26 percent decline in shipments to the U.S. In fact, since the turn of the century, the ability of exchange-rate movements to affect trade and growth in major economies has fallen by more than half, according to Goldman Sachs Group Inc. The findings suggest that ... (full story)