The recent fall of labor's share of GDP in numerous countries is well-documented, but its causes are poorly understood. We sketch a "superstar firm" model where industries are increasingly characterized by "winner take most" competition, leading a small number of highly profitable (and low labor...

From 1963 through 2015, idiosyncratic risk (IR) is high when market risk (MR) is high. We show that the positive relation between IR and MR is highly stable through time and is robust across exchanges, firm size, liquidity, and market-to-book groupings. Though stock liquidity affects the...