We analyze a multiple‐activity, principal‐agent model in which the activities are naturally substitutable for the agent and complementary for the principal. A basic result is that the optimal compensation must cause the agent to view the activities as complements. This complementarity is achieved by employing a compensation scheme that is typically nonmonotone and makes success on multiple dimensions the sole source of large rewards. A number of empirical implications follow, along with explanations for some existing empirical findings. We also discuss applications to compensation in specific occupations.

We examine theories of leverage and debt maturity, focusing on the impact of firms' investment opportunity sets and regulatory environments in determining these policies. Using results on strategic complementarities, we identify sufficient conditions for the theory to have testable implications for reduced-form and structural-equation regression coefficients. Obtaining testable implications for structural equations requires less from the theory but more from the data than the reduced-form specification because it requires an instrumental-variables approach. We examine this trade-off between theory and statistical methods and provide tests using two decades of data for over 5000 industrial firms.

Previous work has addressed the relative vulnerability of different auction schemes to collusive bidding. The common wisdom is that ascending-bid and second-price auctions are highly susceptible to collusion. We show that the details of ascending-bid and second-price auctions, including bidder registration procedures and procedures for information revelation during the auction, can be designed to completely inhibit, or unintentionally facilitate, certain types of collusion. If auctions are designed without acknowledging the possibility of collusion then the design will ignore key features that impact the potential success of colluding bidders.

We provide an incomplete information bargaining framework that captures the effects of differential bargaining power in markets with multiple buyers and multiple suppliers. The market is modeled as a mechanism that maximizes the expected weighted welfare of the firms, subject to the constraints of incentive compatibility, individual rationality, and no deficit. We show that, in this model, there is no basis for the presumption that vertical integration increases equally weighted social surplus, while it is possible that horizontal mergers that appropriately change bargaining weights increase social surplus. Moreover, efficient bargaining implies that in equilibrium noncontractible investments are efficient.

Opportunism in Multilateral Vertical Contracting: Nondiscrimination, Exclusivity, and Uniformity: Comment by Leslie M. Marx and Greg Shaffer. Published in volume 94, issue 3, pages 796-801 of American Economic Review, June 2004

We present a model of Nasdaq that includes the two ways in which marketmakers compete for order flow: quotes and direct payments. Brokers in our model can execute small trades through a computerized system, preferencing arrangements with marketmakers, or vertical integration into market making. The comparative statics in our model differ from those of the traditional model of dealer markets, which does not capture important institutional features of Nasdaq. We also show that the empirical evidence is inconsistent with the traditional model, which suggests that preferencing and vertical integration are important components in understanding Nasdaq.

We analyze the competitive effects of mergers in markets with buyer power. Using mechanism design arguments, we show that without cost synergies, mergers harm buyers, regardless of buyer power. However, buyer power mitigates the harm to a buyer from a merger of symmetric suppliers. With buyer power, a merger increases incentives for entry, increases investment incentives for rivals, and can increase investment incentives for merging parties. Because buyer power reduces the profitability of a merger, it increases the profitability of perfect collusion relative to a merger. Cost synergies can eliminate merger harm but also render otherwise profitable mergers unprofitable.

We discuss the economics literature relevant to the design of centralized two-sided market mechanisms for environments in which both buyers and sellers have private information. The existing literature and the history of spectrum auctions, including the incentive auction currently being designed by the FCC, can be employed to analyze such mechanisms. We compare the revenue– efficiency trade-off in an environment with private information on one side of the market versus the trade-off with private information on both sides of the market; we provide an impossibility theorem for the efficient allocation of goods using a deficit-free mechanism when there is private information on both sides of the market; we discuss practical deficit-free mechanisms for various environments with two-sided private information; and we provide a synthesis to guide market design efforts and related research going forward.

Consignment auctions are two-stage mechanisms to (re)allocate emission permits. Firms are first endowed with permits and then allowed to trade them. We determine theoretically endowments that enable efficient allocation, subject to incentive compatibility, individual rationality, and no deficit. All firms prefer efficient consignment auctions to efficient standard auctions, making them politically palatable. Firms’ investment incentives align with the first-best in efficient consignment auctions. Grandfathering based on efficient long-run allocations induces efficiency-permitting endowments. A simple calibration to data from Southern California’s RECLAIM program validates our no-deficit assumption and shows that grandfathering provides the best theoretical match for the empirically observed endowments.

Platform-based information sharing among competing firms presents challenges for antitrust authorities, yet effective remedies remain unclear. Drawing inspiration from the Informed Sources retail gasoline antitrust case, we develop a theoretical model that offers policy guidance for disrupting anticompetitive coordination facilitated through price-sharing platforms. Removing only one firm from a platform may be ineffective for disrupting such coordination. However, competitive benefits can emerge if (i) at least two firms lack platform access, and (ii) the costs of price leadership are sufficiently high. More broadly, coordinating price increases becomes more difficult when multiple firms cannot quickly observe or respond to rivals' prices.