Human–capital investment and the wage gap

Summary. According to empirical studies, the wage differential by skills evolved non–monotonically in the past decades although the relative supply of skilled labor steadily increased. The present paper provides a theoretical explanation for this finding. In our setting, technological change intertemporally alters the human–capital investment incentives of heterogeneous individuals. As a consequence of changing incentives, the time path of the relative wage is U–shaped while there is a rise in the share of skilled workers. Received: November 28, 2000; revised version: January 30, 2001     

Pricing, learning, and strategic behavior in a single-sale model

Summary. We analyze an infinite horizon model where a seller who owns an indivisible unit of a good for sale has incomplete information about the state of the world that determines not only the demand she faces but also her own valuation for the good. Over time, she randomly meets potential buyers who may have incentives to manipulate her learning process strategically. We show that i) the seller's incentives to post a high price and to experiment are not necessarily monotonic in the information conveyed by a buyer's rejection; and ii) as the discount factors tend to one, there are equilibria where the seller always ends up selling the good at an ex-post individually rational price. Received: January 6, 1999; revised version: July 15, 2000     

Inflation, investment and economic performance: The role of internal financing

This paper studies a link between inflation and economic activity that is built on two hypotheses. First, firms mitigate informational frictions in financial markets by accumulating retained earnings over a period of time. Second, firms allocate earnings among three competing uses - dividends, current investment, and the accumulation of internal funds - and inflation directly distorts this allocation decision as well as the real value of accumulated internal funds. The model predicts that the level of inflation - both unanticipated and expected inflation - as well as the variability of inflation distort firms’ internal financing decisions, increases frictions in financial markets, reduces the level and efficiency of investment, and reduces aggregate output. The marginal effects of inflation are increasing in the inflation rate.     

The equilibrium set of two-player games with complementarities is a sublattice

Summary. I prove that the equilibrium set in a two-player game with complementarities, and totally ordered strategy spaces, is a sublattice of the joint strategy space. Received: May 31, 2001; revised version: October 4, 2002     

Double Moral Hazard,Monitoring, and the Nature of Contracts

generalized double-sided moral-hazard model, with risk-averse parties who mutually monitor each other (to get a reasonable idea of outcome/effort). The model considers trade-off between monitoring costs and moral hazard costs, which are endogenously determined by the extent of monitoring. Using this model, we formally prove a generalized version of Coase's conjecture – that the optimal contract minimizes the agency and risk costs. We then show how varying assumptions about the feasibility or cost of monitoring of the outcome or the worker's effort lead to different contracts being optimal. The analysis is then used to explain the nature of contracts observed in practice under many different situations. We will give an explanation as to why industrial workers typically work under wage contracts, while share contracts are common in agriculture and will explain why profit sharing is more common for senior managers than for the production workers. Received September 19, 2000; revised version received October 30, 1997     

The impact of product diversification strategy on the corporate performance of large Spanish firms

We analyze the impact of product diversification on performance. This topic has been discussed in the literature, and there is no consensus so far as to the significance or the direction of the impact. Performance is measured using Tobin's q for a sample of 103 large, non-financial Spanish firms (1992–1995). Diversification is measured by means of a categorical variable, as suggested by Varadarajan. The principal results indicate that the firms with intermediate levels of product diversification have the highest performance, while the firms with low and high levels of diversification show significantly lower performance, which performance is not significantly different between them.     

The impact of environmental regulation on productivity in German industries

The objective of this paper is to adjust a traditional total factor productivity (TFP) measure for the direct effect of environmental regulation on material and capital input. For this purpose we consider the fact that part of material input and pollution abatement capital have not been used to increase output but to cover the cost of using the environment as a factor of production. Therefore TFP growth rates are lower if part of the material input is allocated to abatement activities instead of producing output. We propose to treat compliance with environmental regulation as an unproductive input linked to the use of productive material input. Our aim is to answer and discuss two questions: How to measure the effect of environmental regulation on TFP, and does the effect matter. We examine data from 1975–1991 for ten pollution intensive German industries.We would like to thank Cornelia Oßwald for valuable research assistance. We are especially grateful to two anonymous referees for many helpful comments.     

Cross-country differences in monetary policy execution and money market rates’ volatility

Volatility patterns in overnight interest rates display differences across industrial countries that existing models—designed to replicate the features of individual countries’ markets—cannot account for. This paper presents an equilibrium model of the overnight interbank market that matches cross-country differences in patterns in interest volatility by incorporating differences in how central banks manage liquidity in response to shocks. Our model is consistent with central banks’ practice of rationing access to marginal facilities when the objective of stabilizing short-term interest rates conflicts with another high-frequency objective, such as an exchange rate target.     

Evolutionary foundations of aggregate-taking behavior

Summary. I show that aggregate-taking behavior is often evolutionarily stable for finite population in symmetric games in which payoff depends only on own strategy and an aggregate. I provide economic examples exhibiting this phenomenon. Received: August 27, 2001; revised version: January 29, 2002 RID="*" ID="*" The paper has profited from the comments of Maria Montero, Burkhard Hehenkamp, Wolfgang Leininger, and Dave Furth. Financial support from the DFG via Postgraduate Programme at the University of Dortmund and via SFB 504 at the University of Mannheim is acknowledged. RID="*" ID="*" Present address: University of Mannheim, SFB 504, L 13, 15, 68131 Mannheim, Germany (e-mail: possajen@sfb504.uni-mannheim.de)     

Effect of credible quality investment with Bertrand and Cournot competition

We show how credible revelation and ability to commit to quality choice effect equilibrium qualities and welfare when product market is either Bertrand or Cournot competition. We show that results depend on the type of competition but not generally on the cost of quality function. We show that with Bertrand competition, the equilibrium qualities are lower with credible commitment. Competition is moderated and producer surplus is higher and consumer surplus lower. With Cournot competition, higher quality will be better but lower quality will be worse with credible commitment. Consumer surplus is always greater with credible commitment and if cost does not increase too quickly with quality, producer surplus will also increase. Thus credible commitment is a collusive device with Bertrand competition but it can improve social welfare with Cournot competition. Received: February 8, 2000; revised version: February 14, 2002 RID="*" ID="*" The idea of this paper originated in the weekly workshops of Mordecai Kurz at Stanford. I am forever in debted to Mordecai and fellow students – Luis Cabral, Peter DeMarzo, John Hillas, Michihiro Kandori, Steve Langois, Patrick McAllister, Steve Sharpe, Peter Streufert, Steve Turnbull and Gyu-Ho Wang – for their criticism and encouragement. I also benefited from comments from Yi-Heng Chen, Jin-Li Hu, Kala Krishna, Jinji Naoto, Thomas J. Prusa, and Shyh-Fang Ueng at various later stages of this work. Last but not least, I am grateful for the detailed comments of the referee.