The Fed Needs to Follow the Rules. But Which One?

The Federal Reserve’s new chairman, Kevin Warsh, plans to convene no fewer than five task forces to review the central bank’s methods and operations. They will ask how the Fed can improve its communications, balance-sheet policy, use of data, understanding of “productivity and jobs in an era of transformation,” and delivery of price stability.

The ambition is admirable, and he is right that all these questions are consequential and worthy of a fresh look. Yet it doesn’t help to split the terrain into so many parcels. Everything comes down to that last item: price stability, which is — or ought to be — the Fed’s overriding purpose. The other questions are subsidiary, and what’s more they overlap, so they can’t be answered independently. It would be a shame if the best and simplest change Warsh could make gets lost in a huddle of task forces.

That long-overdue reform would be to rely more on rules to direct monetary policy — an idea that Warsh has frowned on in the past, without ever clearly saying why.

A monetary rule says how policy should change in response to new information. The Taylor rule is the archetype. It ties the policy interest rate to three components: the so-called neutral interest rate (one that maintains with price stability and maximum employment in the long run); deviations of inflation from the Fed’s target; and deviations of unemployment from maximum employment. If inflation is running above target and the economy is at full employment, for example, the response is to raise the policy rate.

Well, things are rarely so simple. The Taylor rule has many versions, depending on exactly how the variables are defined and measured, how they’re weighted in the formula, how abruptly it tells policy to shift, and so forth.

All of which raises a question: If no single version is unambiguously correct, how does the rule help? Also, central banks surely have to weigh a vast amount of other, frequently conflicting information in judging policy. Maybe the neutral rate is changing for some reason. Are prices distorted by (cough) transitory forces? Is something strange going on in the labor market, affecting the estimate of maximum employment?