Competitive Diffusion

The usual explanation for why the producers of a given product use different technologies involves "vintage-capital": A firm understands the frontier technology, but can still prefer an older, less efficient technology in which it has made specific physical and human capital investments. This paper develops an alternative. "information-barrier" hypothesis: Firms differ in the technologies they use because it is costly for them to overcome the informational barriers that separate them. The paper endogenizes both innovative and imitative effort. The industry life-cycle implications -- declining price and increasing output -- broadly agree with the Gort-Klepper data. Empirically, the paper focuses on the slow spread of Diesel locomotives, which can not be explained by the vintage-capital hypothesis alone. For instance, contrary to that hypothesis, railroads were buying new steam locomotives long after the Diesel first came into use -- exactly as the information-barrier hypothesis would imply.

Jobless Recoveries

Historically, when an economy emerges from recession, employment grows with, or soon after, the resumption of GDP growth. However, following the two most recent recessions in the United States, employment growth has lagged the recovery in GDP by several quarters, a phenomenon thathas been termed the 'jobless recovery.' To many, a jobless recovery defies explanation since it violates both historical patterns and the predictions of traditional macro theory. We show that a recession followed by a jobless recovery is precisely what neoclassical theory predicts when new technology impacts different sectors of the economy unevenly and is slow to diffuse, and sectoral adjustments in the labor market take time to unfold.