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.

By operationalizing the notion of creative destruction, Schumpeterian growth theory generates distinctive predictions on important microeconomic aspects of the growth process (competition, firm dynamics, firm size distribution, cross-firm and cross-sector reallocation) which can be confronted using rich micro data. In this process the theory helps reconcile growth with industrial organization and development economics.

Is more intense product market competition and imitation good or bad for growth? This question is addressed in the context of an endogenous growth model with “step-by-step” innovations, in which technological laggards must first catch up with the leading-edge technology before battling for technological leadership in the future. In contrast to earlier Schumpeterian models in which innovations are always made by outsider firms who earn no rents if they fail to innovate and become monopolies if they do innovate, here we find: first, that the usual Schumpeterian effect of more intense product market competition (PMC) is almost always outweighed by the increased incentive for firms to innovate in order to escape competition, so that PMC has a positive effect on growth; second, that a little imitation is almost always growth-enhancing, as it promotes more frequent neck-and-neck competition, but too much imitation is unambiguously growth-reducing. The model thus points to complementary roles for competition (anti-trust) policy and patent policy.

Beyond DSGE Models: Toward an Empirically Based Macroeconomics by David Colander, Peter Howitt, Alan Kirman, Axel Leijonhufvud and Perry Mehrling. Published in volume 98, issue 2, pages 236-40 of American Economic Review, May 2008

This paper investigates the relationship between product market competition and innovation. We find strong evidence of an inverted-U relationship using panel data. We develop a model where competition discourages laggard firms from innovating but encourages neck-and-neck firms to innovate. Together with the effect of competition on the equilibrium industry structure, these generate an inverted-U. Two additional predictions of the model-that the average technological distance between leaders and followers increases with competition, and that the inverted-U is steeper when industries are more neck-and-neck-are both supported by the data. © 2005 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.

How does firm entry affect innovation incentives in incumbent firms? Microdata suggest that there is heterogeneity across industries. Specifically, incumbent productivity growth and patenting is positively correlated with lagged greenfield foreign firm entry in technologically advanced industries, but not in laggard industries. In this paper we provide evidence that these correlations arise from a causal effect predicted by Schumpeterian growth theory—the threat of technologically advanced entry spurs innovation incentives in sectors close to the technology frontier, where successful innovation allows incumbents to survive the threat, but discourages innovation in laggard sectors, where the threat reduces incumbents' expected rents from innovating. We find that the empirical patterns hold using rich micro panel data for the United Kingdom. We control for the endogeneity of entry by exploiting major European and U.K. policy reforms, and allow for endogeneity of additional factors. We complement the analysis for foreign entry with evidence for domestic entry and entry through imports.

Systemic risk must include the housing market, though economists have not generally focused on it. We begin construction of an agent-based model of the housing market with individual data from Washington, DC. Twenty years of success with agent-based models of mortgage prepayments give us hope that such a model could be useful. Preliminary analysis suggests that the housing boom and bust of 1997-2007 was due in large part to changes in leverage rather than interest rates.