In a comment to last week's post on inflation versus price-level targeting, David Beckworth asks the following (referring back to an even earlier post on nominal gross domestic product [NGDP] targeting):

You refer back to your previous post on NGDP level targeting, but fail to take note of the comments that respond to your concerns about it. Specifically, see the ones by Andy Harless and Gregor Bush. Would love to see your response to those ones. Do you have a response for them? I am listening if you have one.

Here is an excerpt from the Harless comment...

Most people who advocate NGDP targeting today advocate level path targeting, not growth rate targeting. I don't believe that your "historical justification" applies in this case. Indeed, I think it makes the case for level targeting (of either the price level or NGDP, but there are reasons to prefer the latter) relative to the current system which centers on a growth rate target for the price level (in other words, an inflation target).

...and here is the Bush comment:

Just to add to Andy's point, advocates of NGDP level targeting argue that it's precisely because of uncertainty around estimates [of] potential output [that] NGDP targeting should be adopted. They argue that [as] long as the central bank keeps nominal spending on, say, a 5% trend line, there will be neither demand side recessions (mass unemployment) nor high inflation. In other words, AD will be stable and this will produce a stable macroeconomic environment. Whether inflation is 2% and real output [grows] at 3% or inflation is 3% and real output grows at 2% is of no concern.

In the post on NGDP targeting I was in fact thinking about level targeting, and Gregor Bush's last sentence gets to—in fact is—the heart of our disagreement. I am just not willing to concede that anchoring long-term inflation by saying something like "2 percent, 3 percent, whatever" is the path to sustaining central bank credibility. Over the longer term, inflation is the only thing that monetary policy can reliably deliver, as the Federal Open Market Committee (FOMC) has clearly articulated in its statement of longer-run goals and policy strategy:

The inflation rate over the longer run is primarily determined by monetary policy, and hence the Committee has the ability to specify a longer-run goal for inflation. The Committee judges that inflation at the rate of 2 percent, as measured by the annual change in the price index for personal consumption expenditures, is most consistent over the longer run with the Federal Reserve's statutory mandate...

The maximum level of employment is largely determined by nonmonetary factors that affect the structure and dynamics of the labor market. These factors may change over time and may not be directly measurable. Consequently, it would not be appropriate to specify a fixed goal for employment; rather, the Committee's policy decisions must be informed by assessments of the maximum level of employment, recognizing that such assessments are necessarily uncertain and subject to revision.

This excerpt does not imply, of course, that the Fed need slavishly pursue a numerical inflation target in the shorter run and, as I have pointed out before, in his last press conference Chairman Bernanke explicitly indicated that the FOMC does not intend to do so:

The Committee... intends to look through purely transitory fluctuations in inflation, such as those induced by short-term variations in the prices of internationally traded commodities, and to focus instead on the underlying inflation trend.

My price-level targeting post, co-authored with Mike Bryan, was exactly making the point that, over the past couple of decades, the FOMC has essentially delivered on a 2 percent longer-term price-level growth objective, while accepting plenty of shorter-term variability.

In the end, it is an open question whether credibility in delivering price stability, hard won in the '80s and early '90s, could be sustained if the FOMC says it does not care so much about the exact level of the average rate of inflation, even in the long run. To be truthful, I can't give you an answer to that question. But neither can the proponents of NGDP targeting. I just don't feel that this is an opportune time for an experiment.

Update: Scott Sumner responds.

Dave AltigBy Dave Altig, executive vice president and research director of the Atlanta Fed