We construct a measure of aggregate technology change, controlling for imperfect competition, varying utilization of capital and labor, and aggregation effects. On impact, when technology improves, input use falls sharply, and output may fall slightly. With a lag of several years, inputs return...

A typical (roughly) two-digit industry in the United States appears to have constant or slightly decreasing returns to scale. Three puzzles emerge, however. First, estimates tend to rise at higher levels of aggregation. Second, estimates of decreasing returns in many industries contradict...

Productivity rises in booms and falls in recessions. There are four main explanations for procyclical productivity: (i) procyclical technology shocks, (ii) widespread imperfect competition and increasing returns, (iii) variable utilization of inputs over the cycle, and (iv) resource...

Explanations of procyclical productivity playa key role in a variety of business-cycle models. Most of these models, however, explain this procyclicaIity within a representative-firm paradigm. This procedure is misleading. We decompose aggregate productivity changes into several terms, each of...

We estimate that returns to scale are close to constant in two-digit gross output data. Value-added data appear instead to give significant increasing returns. We show why, with imperfect competition, value-added estimates are in general meaningless. We use data on intermediate inputs to correct...

Using data on gross output for two-digit manufacturing industries, we find that an increase in the output of one manufacturing sector has little or no significant effect on the productivity of other sectors. Using value-added data, however, we confirm the results of previous studies which find...

Aggregate productivity and aggregate technology are meaningful but distinct concepts. We show that a slightly-modified Solow productivity residual measures changes in economic welfare, even when productivity and technology differ because of distortions such as imperfect competition. We then...