A running argument between Alan Greenspan and Ben Bernanke, on one side, and a small band of vociferous critics, on the other side, turns on a question easier to pose than to answer: Did the Fed contribute to the credit binge and housing bubble by holding short-term rates too low too long in an effort to ward off deflation in the mid-2000s. Greenspan and Bernanke said: No, and they’ve got numbers to make their case. Now comes a pair of economists from the European Central Bank to make the opposite case.

In a working paper, Angela Maddaloni and Jose-Luis Peydro use data from U.S. and European surveys of bank lending officers to argue that low short-term interest rates led lenders to soften standards for loans to households and corporations. “The softening is even amplified when, at the same time, securitization activity is high, supervision for bank capital is weak, and monetary policy rates have been too low for too long, especially for mortgage loans,” they say.

But low long-term rates, they find, don’t have that same unwelcome effect “somewhat in contrast with the hypotheses of many commentators who argued that the financial crisis was caused by an excessive risk-taking stemming from low levels of long-term interest rates, linked to current account imbalances.” That would be a jab at Bernanke, and his case that the global savings glut is more to blame than anything the Fed did.

“In the recent crisis,” they write, “the impact of low monetary policy rates may have been even greater given the concurrence of three elements: the strong reliance on short-term liabilities to leverage up, a weak supervision for bank capital and the high level of financial innovation, notably securitization.”

Central bankers, they advise, should “pay more attention to financial stability while banking supervision and regulation should take in account” macroeconomic effects.

Read a related Capital column on the risks of the Fed’s current policies.