One of the Things We Know that Ain't So: Why US Labor's Share is not Relatively Stable: Is US labor's share relatively stable?

Robert Solow (1958) argued that, from 1929-1954, U.S. aggregate lab's share was not stable relative to what we would expect given individual industry labor's shares. I confirm and extend this result using data from 1958-1996 that includes 35 industries (roughly 2-digit SIC level) and spans the entire U.S. economy. Changes in industry shares in total value-added contribute negligibly to aggregate labor's share volatility. Industry labor's shares comovement actually adds to aggregate labor's share volatility. These findings highlight economists' imprecise understanding of one of the stylized facts of economic growth. If the great macroeconomic ratio is meaningful, it must be interpreted in terms of long-run, offsetting shifts in "services" industries versus "goods" industries, both in terms of their labor's shares and shares in total value-added.