Now forthcoming in the Journal of Political Economy.

Abstract

We find disparate trend variations in TFP and labor growth across major U.S. production sectors and study their implications for the post-war secular decline in GDP growth. We describe how capital accumulation and the network structure of U.S. production interact to amplify the effects of sectoral trend growth rates in TFP and labor on trend GDP growth. We derive expressions that conveniently summarize this long-run amplification effect by way of sectoral multipliers. These multipliers are quantitatively large and for some sectors exceed three times their value-added shares. We estimate that sector-specific factors have historically accounted for approximately 3/4 of long-run changes in GDP growth, leaving common or aggregate factors to explain only 1/4 of those changes. Trend GDP growth fell by nearly 3 percentage points over the post-war period with the Construction sector alone contributing roughly 1 percentage point of that decline between 1950 and 1980. Idiosyncratic changes to trend growth in the Durable Goods sector then contributed an almost 2 percentage point decline in trend GDP growth between 2000 and 2018. Remarkably, no sector has contributed any steady significant increase to the trend growth rate of GDP in the past 70 years.