Do Prices Determine Vertical Integration?

A number of theories in organizational economics and industrial organization suggest that vertical integration, while costly, increases productivity. It follows from firms' maximizing behaviour that higher prices in the product market ought to induce more integration. Trade policy provides a source of exogenous price variation to assess this prediction: higher tariffs should lead to higher prices and, therefore, to more integration. We construct firm-level vertical integration indices for a large set of countries and industries and exploit variation in applied most-favoured-nation tariffs to examine the impact of tariffs on firm boundaries. The empirical results provide strong support for the view that higher output prices generate more vertical integration. Our estimates of the average price elasticity of vertical integration are in the range 0.4-2.