In a surprise move on Sept. 4, the European Central Bank lowered its main lending rate from 0.15 percent to 0.05 percent — a record low — and pushed the overnight deposit rate further into negative territory — from minus 0.1 percent to minus 0.2 percent.

This means that banks will be charged 0.2 percent for depositing funds with the central bank. The move points to the ECB's sense of crisis that the eurozone economy may suffer prolonged stagnation and fall into deflation.

But there is no guarantee that monetary policy alone will buoy the economy. Reform efforts by individual countries, especially by such major ones as France and Italy, will be necessary if the region is to regain sustained growth.