Yet the Fed has ended up surprising in major ways over the last few months, leading to wild gyrations in markets. The Dow collapsed by 5% between May 21st and June 24th, before surging by 8% to a new record close on Wednesday. Commodity and bond markets have also been quite volatile, with the benchmark 10-year Treasury unusually trading in an almost 50 basis point range.

Changes in underlying economic fundamentals do not warrant such volatility. While the economy continues to heal, it is has remained stuck in a multiyear, low-level growth equilibrium that frustrates job creation and worsens income distribution.

It could be that the Fed is really worried about the upcoming congressional battles over funding the government and lifting the debt ceiling. As illustrated by the debacle of the summer of 2011, a slippage could undermine economic performance. And we should never underestimate the appetite of our polarized Congress for self-manufactured challenges. Having said this, the Fed usually prefers to be reactive rather than proactive in such situations.

It is also hard to argue that the Fed has made a major discovery about the longer-term impact of what is after all a highly experimental policy approach. If anything, our central bankers (and, I would argue, everybody else) are essentially in the dark when it comes to the specific evolution over time of what Mr. Bernanke labeled back in 2010 the “benefits, costs and risks” of prolonged reliance on unconventional monetary policy.

We have to go elsewhere to explain the Fed’s unusual surprises. And my preferred explanation at this point — based on partial information and a gut feel — has to do with decision making under considerable uncertainty and changing leadership.

When faced with a challenging decision, we all love focusing on what can go right. It is our natural comfort zone. Yet, particularly in circumstances of extreme uncertainty, it is also important to assess the potential scale and scope of what can go wrong.

The Fed already has a feel for this.

The mere mention of a taper last May did more than cause unusual market volatility. It contributed to a sudden adverse U-turn in the prospects for interest rate sensitive sectors of the economy (including a 14 percent decline in home purchase applications, 66 percent drop in the refinancing index, and 18 percent fall in home affordability). It also contributed to the difficulties emerging economies’ face in maintaining high growth.

Faced with this experience, and knowing that they could end up making a policy mistake (even though they are trying their utmost to avoid it), Fed officials may well prefer excessive monetary accommodation to premature tightening. The expected change in leadership may well serve to accentuate this.

How about the implications for the rest of us?