Vertical Integration and Competition

This paper is part of a research program analyzing how competition affects aggregate innovative activity through its effects on firms’ organization. In previous work (Aghion et al., 2005a), we found an inverted-U shaped relationship between competition and innovation. Our explanation emphasized the “composition effect” of competition on the steady-state distribution of technological gaps across industries. Our focus here is on firms’ decisions whether or not to integrate vertically with their suppliers. We provide evidence of a U-shaped relationship between competition and vertical integration. Our explanation is based on the following idea: a moderate increase in product market competition will reduce a producer’s incentive to integrate by improving the outside options of her nonintegrated suppliers and hence raising their incentive to innovate. Too much competition will raise the producer’s incentive to integrate, however, by allowing nonintegrated suppliers to capture most of the innovation surplus. Finding a U-shaped relationship between competition and vertical integration sheds light on the debate over the “Transaction Cost Economics” (TCE) approach to vertical integration pioneered by Oliver Williamson (1975, 1985) versus the “Property Right Theory” (PRT) approach developed by Sanford Grossman and Oliver Hart (1986) and by Hart and John Moore (1990). According to the TCE approach, vertical integration is a way for contracting parties involved in a specific relationship to limit ex post bargaining inefficiencies due to holdup and thereby minimize the loss in ex ante investment that would result from it. This approach thus predicts a positive correlation between vertical integration and the degree of relation specificity. According to the PRT approach, the ownership structure will affect not so much the ex post bargaining efficiency as the relative bargaining powers of the (two) contracting parties, and therefore their relative ex ante investment incentives. Thus, while vertical integration should enhance both parties’ investments positively in the TCE approach by reducing the extent of ex post inefficiency, in the PRT approach ownership by one party, say the buyer, will enhance the buyer’s ex ante incentives at the expense of the seller’s, as it enhances the buyer’s bargaining power ex post at the expense of the seller’s. Thus, the TCE approach predicts that increased competition on the producer’s (or supplier’s) market, which reduces the overall degree of asset specificity, should therefore reduce the need for vertical integration in order to preserve ex ante investment incentives by either party. On the other hand, as we show below, the PRT approach allows the U-shaped relationship between vertical integration and competition that we find empirically. † Discussants: Sam Kortum, University of Minnesota; Mark Duggan, University of Maryland; Joel Waldfogel, University of Pennsylvania; Shane Greenstein, Northwestern University.