Do top wealth and capital income shares move in parallel?
Core argument: Auten and Splinter argue that when passthrough business income is fully included, their top 1% non-housing "capital" income share rose 5 percentage points from 1989 to 2019, about two-thirds of the Federal Reserve's estimated rise in top 1% wealth shares.
PSZ suggest that top wealth and capital income shares should run parallel over the long run. This is a problematic assumption. Economic changes can push down capital income shares relative to wealth shares. Most importantly, interest rates fell dramatically between 1989 and 2019—the federal funds effective rate fell from 9 to 2%. This decreased the ratio of interest-income to bond-wealth and therefore falling interest rates likely increased the gap between top income and wealth shares. Also, much of top wealth patterns are driven by passthrough business, but this is fully or two-thirds excluded from PSZ’s definition of “capital” income here. When fully including passthrough business, the Auten–Splinter top 1% non-housing “capital” income share increased by 5 percentage points between 1989 to 2019, about two-thirds of the Federal Reserve’s estimated increase in top 1% wealth shares. Therefore, the Auten-Splinter estimates are consistent with increasing top wealth shares.




