Deciphering the Fall and Rise in the Net Capital Share: Accumulation or Scarcity?

In the postwar era, developed economies have experienced two substantial trends in the net capital share of aggregate income: a rise during the last several decades, which is well known, and a fall of comparable magnitude that continued until the 1970s, which is less well known. Overall, the net capital share has increased since 1948, but once disaggregated this increase turns out to come entirely from the housing sector: the contribution to net capital income from all other sectors has been zero or slightly negative, as the fall and rise have offset each other. Several influential accounts of the recent rise emphasize the role of increased capital accumulation, but this view is at odds with theory and evidence: it requires empirically improbable elasticities of substitution, and it presumes a correlation between the capital-income ratio and capital share that is not visible in the data. A more limited narrative that stresses scarcity and the increased cost of housing better fits the data.