PRODUCT VARIETY AND COMPETITION IN THE RETAIL MARKET FOR EYEGLASSES*

I use original data on eyewear retailers in a cross‐section of U.S. markets to study how firms' product range choices vary with the degree of local competition. Market level regressions show average per firm variety declining in the number of rivals. In regressions at the firm level, taking account of spatial differentiation within each market, a non‐monotonic relationship between product ranges and competition is apparent. As the number of nearby rivals increases, per firm variety may first rise before eventually declining. Explanations for this pattern are offered, in terms of a tradeoff between business stealing and clustering effects.     

Inflation and Unit Labor Cost

We study two decompositions of inflation, π, motivated by the standard New Keynesian pricing equation of Gali, Gertler, and Sbordone. The first uses four components: lagged π, expected future π, real unit labor cost (ψ), and a residual. The second uses two components: fundamental inflation (discounted expected future ψ) and a residual. We find large low‐frequency differences between actual and fundamental inflation. From 1999 to 2011 fundamental inflation fell by more than 15 percentage points, while actual inflation changed little. We discuss this discrepancy in terms of the data (a large drop in labor's share of income) and through the lens of a canonical structural model.     

Slack and Cyclically Sensitive Inflation

We investigate the flattening Phillips relation by making two departures from standard specifications. First, we measure slack using real activity variables that are bandpass filtered or year-over-year changes in activity (these are similar), instead of gaps. Second, we study the components of inflation instead of the standard aggregates. We find that some inflation components have strong and stable correlations with the cyclical component of real activity; these components tend to be relatively well-measured and domestically determined. Other components, typically prices that are poorly measured or internationally determined, have weak and/or unstable correlations with cyclical activity. We construct a new inflation index, cyclically sensitive inflation, that weights the components by their joint cyclical covariation with real activity. The index has strong and stable correlations with cyclical activity and provides a real-time measure of cyclical movements in inflation.