John Kennes

Bidding for money

We analyze monetary exchange in a model that allows for directed search and multilateral matches. We consider environments with divisible goods and indivisible money, and compare the results with those in models that use random matching and bilateral bargaining. Two different pricing mechanisms are used: ex ante price posting, and ex post bidding (auctions). Also, we consider settings both with and without lotteries. We find that the model generates very simple and intuitive equilibrium allocations that are similar to those with random matching and bargaining, but with different comparative static and welfare properties.

RESIDUAL WAGE DISPARITY AND COORDINATION UNEMPLOYMENT

How much of residual wage dispersion can be explained by an absence of coordination among firms? To answer, we construct a dynamic directed search model with identical workers where firms can create high- or low-productivity jobs and are uncoordinated in their offers to workers, calibrated to the U.S. economy. Workers can exploit ex post opportunities once approached by firms, and can conduct on-the-job search. The stationary equilibrium wage distribution is hump-shaped, skewed significantly to the right, and, with baseline parameters, generates residual dispersion statistics 75-90% of those found empirically. However, the model underestimates the average duration of unemployment. Copyright 2006 by the Economics Department Of The University Of Pennsylvania And Osaka University Institute Of Social And Economic Research Association.

Auctions Beat Posted Prices in a Small Market

In a model with two buyers and sellers we consider the choice of sales mechanism from three possibilities: posted prices, and auctions with and without reserve prices. With homogenous goods, sellers expected revenues are highest when both sellers auction with reserve prices 33% higher than if posting prices and 100% higher than if auctioning without reserve prices. When sellers can choose their mechanism before choosing prices, both sellers auction with a reserve price in the dominant strategy equilibrium. With heterogenous goods, the equilibrium with posted prices is inefficient (Montgomery (1991)) but the equilibria with both types of auctions are efficient.

Directed search, unemployment and public policy

We examine the effects of public policy parameters in a simple directed search model of the labour market, and contrast them with those in standard random matching models with Nash bargaining. Both finite and limit versions of the directed search model are considered, and the value of the limit model as an approximation of the finite one is assessed. As with the random matching model, job creation is the key channel through with the policy parameters effect the equilibrium of the directed search model. Both comparative static effects of the policy parameters and optimal configurations are identified.

Competitive Auctions: Theory and Application

The theory of competitive auctions offers a coherent framework for modelling coordination frictions as a non-cooperative game. The theory represents an advancement over cooperative approaches that make exogenous assumptions about how output is divided between buyers and sellers and about the forces that bring buyers and sellers into local markets. Moreover, unlike price posting models, which fix the terms of trade prior to matching, competitive auction models have a bidding process that allocates the good (or service) to the highest valuation bidder at a price equal to the second highest valuation. Therefore, the competing auction model is more robust to problems in which there are heterogenous valuations. This paper develops the theory of competitive auctions and applies it to a number of practical problems in microeconomics, labor economics, industrial organization, investment theory and monetary economics.

Efficient search and recruiting: Choosing sides in matching games

Abstract This paper looks for sharing rules which implement efficient allocations in a simple matching game. It is shown that efficiency is possible even if the matching technology does not display constant returns to scale.

Friction Induced Trade

This paper develops a simple model of friction induced international trade. Frictions restrict the substitutability of goods and consequently similar sellers choose to offer quality differentiated products in equilibrium. International comparative advantage then leads countries to trade even though there might be a strong bias for domestically produced goods. If trade is induced by frictions, the development of information technology leads to less international trade and higher wages. Friction induced trade is also associated with price dispersion, which falls as frictions are reduced.

Coordination Frictions and Job Heterogeneity

We develop a competing auction model of a labor market with a continuum of heterogeneous workers and firms. We estimate this model and compare it to closely related models of price posting using Danish data on wages and productivities. Assuming heterogeneous workers with no comparative advantage, we find that each model gives a reasonable approximation of the statistical moments of both the wage and productivity distribution. A sensitivity analysis then draws out further implications of the theory. We explain how the feasible matchings between workers and firms changes as the worker moves up the job ladder, how the identification of assortative matching is fundamentally different in directed and undirected search models, how our theory accounts for business cycle facts related to inter-temporal changes in job offer distributions, and how our model could also be used to identify the contributions of specific versus general human capital.