Feature selection methods involving support vector machines for prediction of insolvency in non‐life insurance companies

We propose two novel approaches for feature selection and ranking tasks based on simulated annealing (SA) and Walsh analysis, which use a support vector machine as an underlying classifier. These approaches are inspired by one of the key problems in the insurance sector: predicting the insolvency of a non‐life insurance company. This prediction is based on accounting ratios, which measure the health of the companies. The approaches proposed provide a set of ratios (the SA approach) and a ranking of the ratios (the Walsh analysis ranking) that would allow a decision about the financial state of each company studied. The proposed feature selection methods are applied to the prediction the insolvency of several Spanish non‐life insurance companies, yielding state‐of‐the‐art results in the tests performed. Copyright © 2005 John Wiley & Sons, Ltd.     

Mixed Duopoly,Merger and Multiproduct Firms

The literature on mergers has extensively analyzed the decision to merge by private firms, but it has not considered the decision to merge by private and public firms. We assume that when a private firm and a public firm merge (or when one of them acquires the other), they set up a multiproduct firm in which the government owns an exogenous percentage stake. In this framework, we show that the decision to merge by firms depends on the degree to which goods are substitutes and on the percentage of the shares owned by the government in the multiproduct firm.     

Publishing performance in economics: Spanish rankings (1990–1999)

Abstract. This paper contributes to the growing literature that analyses the Spanish publishing performance in Economics throughout the 1990s. Several bibliometric indicators are used in order to provide Spanish rankings (of both institutions and individual authors) based on Econlit journals. Further, lists of the ten most influential authors and articles over that period, in terms of citations, are reported. We are grateful to many colleagues who made very useful remarks to preliminary versions of this paper, as well as to two anonymous referees. We are particularly indebted to Xavier Sala-i-Martín, without whose invaluable help this work would not have been possible. All errors or omissions are of our exclusive responsibility.     

Economic mechanisms for environmental protection: Business versus market transaction costs

This study presents theoretical arguments and evidence that attempt to show the contribution of economic mechanisms typical of a business for resolving problems of environmental protection. Firstly, a brief synopsis is given of the classic solutions that environmental economics proposes for correcting environmental externalities. Next, the benefit of expanding these two mechanisms is discussed so that they include those intermediate mechanisms for which it is not possible to clearly establish if they are developed within the domain of the market or the business. The study's focus resides in the fact that the explicit expansion of the range of solutions proposed from a macroeconomic point of view establishes a connecting point between environmental economics and business economics, an area in which academic attention to environmental matters has been significantly less. The present work forms part of research project SEC2002-00835, financed by MCYT-FEDER.     

Enforcing Emissions Trading when Emissions Permits are Bankable

We propose enforcement strategies for emissions trading programs with bankable emissions permits that guarantee complete compliance with minimal enforcement costs. Our strategies emphasize imperfect monitoring supported by a high unit penalty for reporting violations, and tying this penalty directly to equilibrium permit prices. This approach is quite different from several existing enforcement strategies that emphasize high unit penalties for emissions in excess of permit holdings. Our analysis suggests that a high penalty for excess emissions cannot be used to conserve monitoring effort, and that it may actually increase the amount of monitoring necessary to maintain compliance.The authors are grateful to Anthony Heyes and three anonymous referees for their valuable comments. Partial support for this research was provided by the Cooperative State Research Extension, Education Service, U. S. Department of Agriculture, Massachusetts Agricultural Experiment Station under Project No. MAS00871.     

Growth,Convergence, and Social Cohesion in the European Union

The aim of this paper is to analyze the economic and social cohesion in the European Union. There are different factors to explain the convergence process and besides, empirical findings are not conclusive. To the European Union, GDP per head interregional differences have decreased for certain periods but it has remained unchanged or even increased for others periods. The second report on the economic and social cohesion indicates that some decades are necessary to eliminate regional differences. These differences in regional GDP are mainly explained by differences in their productive structures, degree of innovate activity, communications structures, which depend on the relative level of transport infrastructures, and manpower qualifications. This analysis allows us to obtain some conclusions to the economic policies and the social cohesion. A preliminary version of this paper was presented in the 57th International Atlantic Conference, held in Lisbon, Portugal, March 10–14, 2004.     

Recursive utility with unbounded aggregators

A new framework is presented for the study of the existence and uniqueness of solutions to the Koopmans’ equation in the unbounded case, that is based on the contraction mapping approach. In the bounded below case with bounded consumption streams, uniqueness of the solution in the whole class of weak-star continuous utility functions is obtained. When the aggregator is unbounded below and/or consumption streams are unbounded, existence of a weak-star continuous solution is shown, and a simple criterium to check the sufficient conditions for existence is provided. Juan Pablo Rincón-Zapatero and Carlos Rodríguez-Palmero gratefully acknowledge financial support by the Ministerio de Educación y Ciencia and FEDER funds under Research Projects MTM2005-06534 and SEJ2005-08709/ECON, respectively, and by Consejería de Educación de la Junta de Castilla y León under Research Projects VA99/04 and VA017B05, respectively. This paper has substantially benefited from the comments of an anonymous referee. Particular and special thanks are due to Robert Becker for his very helpful comments and valuable suggestions.     

Trees and decisions

Summary. The traditional model of sequential decision making, for instance, in extensive form games, is a tree. Most texts define a tree as a connected directed graph without loops and a distinguished node, called the root. But an abstract graph is not a domain for decision theory. Decision theory perceives of acts as functions from states to consequences. Sequential decisions, accordingly, get conceptualized by mappings from sets of states to sets of consequences. Thus, the question arises whether a natural definition of a tree can be given, where nodes are sets of states. We show that, indeed, trees can be defined as specific collections of sets. Without loss of generality the elements of these sets can be interpreted as representing plays. Therefore, the elements can serve as states and consequences at the same time.Received: 23 January 2003, Revised: 2 November 2003, JEL Classification Numbers: C72, D70. Correspondence to: Klaus RitzbergerWe are grateful to Larry Blume, Ariel Rubinstein, Jörgen Weibull, an anonymous referee, and seminar participants at the universities of Vienna, Salamanca, and Heidelberg for helpful comments. Financial support from the Austrian Science Fund (FWF) under project P15281 is also gratefully acknowledged.