New Argument for a Higher Inflation Target

On voxeu.org, Philippe Aghion, Antonin Bergeaud, Timo Boppart, Peter Klenow, and Huiyu Li discuss their recent work on the measurement of output and whether measurement bias can account for the measured slowdown in productivity growth. While the work is mostly relevant to discussions of the productivity slowdown and secular stagnation, I was interested in a corollary that ties it to discussions of the optimal level of the inflation target.

The authors note the high frequency of "creative destruction" in the US, which they define as when "products exit the market because they are eclipsed by a better product sold by a new producer." This presents a challenge for statistical offices trying to measure inflation:

The standard procedure in such cases is to assume that the quality-adjusted inflation rate is the same as for other items in the same category that the statistical office can follow over time, i.e. products that are not subject to creative destruction. However, creative destruction implies that the new products enter the market because they have a lower quality-adjusted price. Our study tries to quantify the bias that arises from relying on imputation to measure US productivity growth in cases of creative destruction.

They explain that this can lead to mismeasurement of TFP growth, which they quantify by examining changes in the share of incumbent products over time:

If the statistical office is correct to assume that the quality-adjusted inflation rate is the same for creatively destroyed products as for surviving incumbent products, then the market share of surviving incumbent products should stay constant over time. If instead the market share of these incumbent products shrinks systematically over time, then the surviving subset of products must have higher average inflation than creatively destroyed products. For a given elasticity of substitution between products, the more the market share shrinks for surviving products, the more the missing growth.

From 1983 to 2013, they estimate that "missing growth" averaged about 0.63% per year. This is substantial, but there is no clear time trend (i.e. there is not more missed growth in recent years), so it can't account for the measured productivity growth slowdown.

The authors suggest that the Fed should consider adjusting its inflation target upwards to "get closer to achieving quality-adjusted price stability." A few months ago, 22 economists including Joseph Stiglitz and Narayana Kocherlakota wrote a letter urging the Fed to consider raising its inflation target, in which they stated:

Policymakers must be willing to rigorously assess the costs and benefits of previously-accepted policy parameters in response to economic changes. One of these key parameters that should be rigorously reassessed is the very low inflation targets that have guided monetary policy in recent decades. We believe that the Fed should appoint a diverse and representative blue ribbon commission with expertise, integrity, and transparency to evaluate and expeditiously recommend a path forward on these questions.

The letter did not mention this measurement bias rationale for a higher target, but the blue ribbon commission they propose should take it into consideration.