The paper offers a new theoretical framework to examine the role of intermediaries between creators and users of new inventions. We find that uncertainty about the profitability of investing in new inventions generates a basis for intermediation. An intermediary may provide an opportunity to...

We study two-sided markets with a finite numbers of agents on each side, and with two-sided incomplete information. Agents are matched assortatively on the basis of costly signals. A main goal is to identify conditions under which the potential increase in expected output due to assortative...

We introduce product differentiation into the analysis of price competition in markets where suppliers test customers in order to assess whether they will pay for received goods or services. We find that, if the degree of differentiation is sufficiently high, suppliers may improve the average...

We study a model where the aggregate trading of currency speculators reveals new information to the central bank and affects its policy decision. We show that the learning process gives rise to coordination motives among speculators leading to large currency attacks and introducing...

We study a model where a capital provider learns from the price of a firm’s security in deciding how much capital to provide for new investment. This feedback effect from the financial market to the investment decision gives rise to trading frenzies, where speculators all wish to trade like...

We propose a new theory of suboptimal risk-taking based on contractual externalities. We examine an industry with a continuum of firms. Each firm's manager exerts costly hidden effort The productivity of effort is subject to systematic shocks. Firms' stock prices reflect their performance...

We study ffort and risk-taking behaviour in an economy with a continuum of principal-agent pairs where each agent exerts costly hidden effort. When the industry productivity is uncertain, agents have motivations to match the industry average effort, which results in contractual externalities....

We study multi-object auctions where agents have private and additive valuations for heterogeneous objects. We focus on the revenue properties of a class of dominant strategy mechanisms where a weight is assigned to each partition of objects. The weights influence the probability with which...

We study the allocation of several heterogenous, commonly ranked objects to impatient agents with privately known characteristics who arrive sequentially according to a Poisson or renewal process. We analyze and compare the policies that maximize either welfare or revenue. We focus on two cases:...

We study the effects of allocative and informational externalities in (multi-object) auctions and related mechanisms. Such externalities naturally arise in models that embed auctions in larger economic contexts. In particular, they appear when there is downstream interaction among bidders after...