The European Central Bank acts, as the name implies, as a central bank for nations using the Euro as their national currency. Opponents of the Euro point to this “one size fits all” strategy as a weakness of the concept as it doesn’t allow nation states within the block to change interest rates within their countries in response to local inflation or economic stagnation. Those who support the concept point out that the weaker member states get the protection of the currency muscle of the larger members of the bloc which protects them from the effects of currency fluctuations on raw materials, a stable price for exports and protection against speculative raids on the currency of a smaller nation – imagine what would have happened to the value of the Drachma had Greece not been a member of the Eurozone at the time of the Global Financial Crisis and the European Sovereign Debt Crisis (to which Greece contributed hugely, of course).
Inevitably, therefore, the ECB has to take an holistic approach to the economic situation in the Eurozone and that must be conservative in nature, for obvious reasons. Given that Eurozone inflation is well constrained and below the ECB target and that, even in Germany, the economic recovery is modest (to say the least) it was always likely that the ECB would leave interest rates unchanged at 0% which is what they did.
The ECB has made no further alteration to its QE programme this month, having announced an extension until the end of 2017, but a reduction in the monthly injection of cash from 80 to 60 billion Euros.