Challenges to Mismeasurement Explanations for the US Productivity Slowdown

摘要

What I have termed the "mismeasurement hypothesis" argues that true productivity growth has not slowed (or has slowed considerably less than measured) since 2004, but recent gains have not been reflected in productivity statistics, either because new goods' total surplus has shifted from (measured) revenues to (unmeasured) consumer surplus, or because price indices are overstated. My evaluation focuses on four pieces of evidence that pose challenges for mismeasurement-based explanations for the productivity slowdown that the US economy has been experiencing since 2004. Two patterns—the size of the slowdown across countries is uncorrelated with the information and communications technology intensities of those countries' economies, and the GDI-GDP gap began opening before the slowdown and in any case reflects capital income growth—are flatly inconsistent with the implications of the mismeasurement hypothesis. Two others—the modest size of the existing literature's estimates of surplus from internet-linked products and the large implied missing growth rates of digital technology industries that the mismeasurement hypothesis would entail—show the quantitative hurdles the hypothesis must clear to account for a substantial share of what is an enormous amount of measured output lost to the slowdown (around $9,300 per person per year).