Component efficient solutions in line-graph games with applications

Recently, applications of cooperative game theory to economic allocation problems have gained popularity. We investigate a class of cooperative games that generalizes some economic applications with a similar structure. These are the so-called line-graph games being cooperative TU-games in which the players are linearly ordered. Examples of situations that can be modeled like this are sequencing situations and water distribution problems. We define four properties with respect to deleting edges that each selects a unique component efficient solution on the class of line-graph games. We interpret these solutions and properties in terms of dividend distributions, and apply them to economic situations. This research has been done while the third author was visiting Tinbergen Institute at the Free University, Amsterdam. The research is part of the Research Programme “Strategic and Cooperative Decision Making” at the Department of Econometrics. Financial support from the Netherlands Organization for Scientific Research (NWO) in the framework of the Russian-Dutch programme for scientific cooperation, is gratefully acknowledged. The third author also appreciates partial financial support from the Russian Leading Scientific Schools Fund (grant 80.2003.6) and Russian Humanitarian Scientific Fund (grant 02-02-00189a). We thank three anonymous referees for their valuable comments.     

Unemployment dynamics in an OLG economy with public pensions

Pension benefits in old age establish a disincentive to save in youth, thereby yielding lower levels of capital stock and the wage rate. As a result, the trade union has an incentive to change the composition of its two targets: employment and the wage rate. This paper develops a model that includes employment effects of public pensions via capital accumulation and union wage setting. Within this framework, we consider how contribution rates to the pension system influence the level and time path of the unemployment rate. It is demonstrated that (1) a higher contribution rate results in a lower unemployment rate, and (2) the economy with a high (low) contribution rate experiences monotone convergence towards (oscillatory convergence towards or a period-2 cycle around) the steady state. The author would like to thank an anonymous referee, Kazutoshi Miyazawa, and seminar participants at Osaka University for their useful comments and suggestions, and Masako Ikefuji and Hiroaki Yamagami for their research assistance. Financial support from the Japan Society for the Promotion of Science (JSPS) through a Grant-in-Aid for Young Scientists (B) (No.17730131), the Asahi Glass Foundation, the Japan Economic Research Foundation and the 21st Century COE Program (Osaka University) is gratefully acknowledged. All remaining errors are mine.     

Neighborhood structure and the evolution of cooperation

This paper deals with the problem of explaining the survival of cooperative behavior in populations in which each person interacts only with a small set of social ‘neighbors’, and individuals adjust their behavior over time by myopically imitating more successful strategies within their own neighborhood. We identify two parameters—the interaction radius and the benefit–cost ratio—which jointly determine whether or not cooperation can survive. For each value of the interaction radius, there exists a critical value of the benefit–cost ratio which serves as the threshold below which cooperation cannot be sustained. This threshold itself declines as the interaction radius rises, so there is a precise sense in which dense networks are more conducive to the evolution of cooperation.     

Existence of Equilibria in Matching Models of Money: A New Technique

This paper develops a new technique for proving the existence and indeterminacy of monetary equilibria in money search models with divisible money. Our technique is substantially simpler than standard constructive proofs in the literature. This paper is based on the second half of Kamiya and Shimizu (2002). We are very grateful to the associate editor and an anonymous referee of this journal for their very detailed suggestions and comments. This research is financially supported by Grant-in-Aid for Scientific Research from JSPS and MEXT. The second author also acknowledges the financial support by Zengin Foundation for studies on Economics and Finance.     

The Borda rule,Condorcet consistency and Condorcet stability

Summary. The Borda rule is known to be the least vulnerable scoring rule to Condorcet inconsistency, Saari (2000). Such inconsistency occurs when the Condorcet winner (the alternative which is preferred to any other alternative by a simple majority) is not selected by the Borda rule. This note exposes the relationship between the Borda rule and the Condorcet q-majority principle as well as the Condorcet q-majority voting rule. The main result establishes that the Borda rule is Condorcet q-majority consistent when where k is the number of alternatives. The second result establishes that is the minimal degree of majority decisiveness corresponding to the Borda rule under sincere voting. The same majority is required to ensure decisiveness under the Borda rule and to ensure that a q-rule (the generalized q-majority Condorcet rule) is a voting rule. Received: April 8, 2002; revised version: July 17, 2002 Correspondence to:S. Nitzan     

Environmental tax policy in a model of growth cycles

Summary. The purpose of this paper is to consider environmental taxation which would control emissions of firms in a model of growth cycles. In the model presented below, the economy may experience two phases of growth and environmental quality: “the no-innovation growth regime” and “the innovation-led growth regime”. Aggregate capital and environmental quality remain constant in the no-innovation growth regime, while they perpetually increase in the innovation-led growth regime. The paper shows that the tax plays a key role in determining whether the economy stably converges to one of the two regimes or fluctuates permanently between them. It also shows that there is a critical level of the tax and that the economy obtains higher growth rates of capital and environmental quality by raising (or reducing) the tax if the initial tax is below (or above) the critical level. Received: April 2, 2001; revised version: March 21, 2002 RID="*" ID="*" This research reported here was conducted within the research project “Project on Intergenerational Equity” at Institute of Economic Research, Hitotsubashi University. I am deeply grateful to an anonymous referee for his or her insightful comments, which greatly improved the paper. I also thank Hiroshi Honda, Yasuo Maeda, Yuji Nakayama, and participants in workshops at Hitotsubashi University, Kyoto University, Nagoya University, Osaka University, University of Tsukuba, Yokohama National University, and University of Tokyo for their valuable comments and suggestions. Any remaining errors are mine.     

Amended final-offer arbitration over an uncertain value: A comparison with CA and FOA

Arbitration is increasingly employed to resolve disputes. Two arbitration mechanisms, conventional arbitration (CA) and final-offer arbitration (FOA) are commonly utilized, but previous theoretical and empirical research has found that they are unsatisfactory. Several alternative mechanisms have been proposed, but ultimately laboratory research has found that they do not offer an improvement. An exception is amended final-offer arbitration (AFOA), which not only has desirable theoretical properties but also has been demonstrated to outperform FOA in the laboratory. This study provides a direct laboratory comparison of AFOA with CA. Also, by utilizing an environment with an uncertain payoff to one of the parties, this study tests the robustness of AFOA’s performance relative to FOA. The results indicate that AFOA does outperform FOA, but that AFOA is only weakly better than CA. JEL Classification C7, C9, J5, K4     

Commodity price cycles and heterogeneous speculators: a STAR–GARCH model

We propose an empirical commodity market model with heterogeneous speculators. While the power of trend-extrapolating chartists is constant over time, the symmetric impact of stabilizing fundamentalists adjusts endogenously according to market circumstances: Using monthly data for various commodities such as cotton, sugar or zinc, our STAR–GARCH model indicates that their influence positively depends on the distance between the commodity price and its long-run equilibrium value. Fundamentalists seem to become more and more convinced that mean reversion will set in as the mispricing enlarges. Commodity price cycles may thus emerge due to the nonlinear interplay between different trader types. The paper represents the authors’ personal opinion and does not necessarily reflect the views of the Deutsche Bundesbank.     

Regulatory and environmental effects on public transit efficiency: a mixed DEA-SFA approach

This paper assesses the impact of regulatory and environmental factors and statistical noise on the efficiency of public transit systems within a DEA-based framework. Using a panel of Italian companies, we implement a DEA-SFA mixed approach based on [H.O. Fried et al. (2002) Journal of Productivity Analysis, 17(1–2), 157–174] to decompose DEA inefficiency measures into three components: exogenous effects, managerial inefficiency and stochastic events. Besides providing evidence on the determinants of input-specific efficiency differentials across companies, the results point out that managerial skills play a minor role, and emphasize the relevance of regulatory policies aimed at replacing cost-plus subsidization with high-powered incentive contracts as well as improving environmental conditions of public transit networks.