"The commodity markets are reflecting reduced demand [from Asia], but in some cases, particularly energy and agriculture, oversupply has been the real problem. People are missing the distinction between a demand shock and a supply shock," says Steve Strongin, head of commodities research at Goldman Sachs in New York.

Meanwhile, with a single interest rate and one currency across Europe, member countries will lose discretion to adjust monetary policies to demand shocks while the automatic responses that markets provide to such shocks — falling real interest rates and falling currencies — will be gone.

Preliminary research by Joanna Gray and others indicates that full indexing increases macroeconomic stability if the economy only suffers from demand shocks, but in the presence of supply shocks aggravates both inflation and recession.