Market Exposure and Endogenous Firm Volatility over the Business Cycle

Firms that reach a larger number of markets diversify market-specific demand risk at a cost. The model is driven only by total factor productivity shocks and captures the business cycle properties of firm-level volatility. Using a panel of U.S. firms (Compustat), the authors empirically document the countercyclical nature of firm-level volatility. They then match this panel to Compustat's Segment data and the U.S. Census's Longitudinal Business Database (LBD) to show that, consistent with their model, measures of market reach are procyclical, and the countercyclicality of firm-level volatility is driven mostly by those firms that adjust the number of markets to which they are exposed. This finding is explained by the negative elasticity between various measures of market exposure and firm-level idiosyncratic volatility the authors uncover using Compustat, the LBD, and the Kauffman Firm Survey.