Optimists see the stronger dollar as a simple means to export America’s recovery elsewhere; but that too is more complicated than it first looks. The greenback is certainly on the rise, fuelled by faster growth and the prospects of tighter monetary policy from the Fed. On a trade-weighted basis, it is up 6.3% since July, and is at a six-year high against the yen and two-year high against the euro (see article). It looks likely to go higher: dollar surges tend to stretch over several years.