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.     

Statistical Decision Problems and Bayesian Nonparametric Methods

This paper considers parametric statistical decision problems conducted within a Bayesian nonparametric context. Our work was motivated by the realisation that typical parametric model selection procedures are essentially incoherent. We argue that one solution to this problem is to use a flexible enough model in the first place, a model that will not be checked no matter what data arrive. Ideally, one would use a nonparametric model to describe all the uncertainty about the density function generating the data. However, parametric models are the preferred choice for many statisticians, despite the incoherence involved in model checking, incoherence that is quite often ignored for pragmatic reasons. In this paper we show how coherent parametric inference can be carried out via decision theory and Bayesian nonparametrics. None of the ingredients discussed here are new, but our main point only becomes evident when one sees all priors—even parametric ones—as measures on sets of densities as opposed to measures on finite-dimensional parameter spaces.     

The toxic syndrome proceedings in Spain

The author, who has been counsel for the injured in the Spanish olive oil proceedings, reports about the health, political and legal issues of this the greatest tragic event in recent Spanish history. The complexity of the marketing processes has made it difficult to trace the criminal responsibilities of the traders of denatured oil. The civil servants in charge of control and supervision have so far been exempted from the proceedings. The author analyses the legal problems and makes suggestions as to the handling of such cases, including compensation.

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Die spanischen Strafverfahren im Zusammenhang mit dem Olivenölskandal

Zusammenfassung Der Bericht untersucht die Entstehung und Abwicklung des spanischen Strafverfahrens im Olivenölskandal. Im Jahre 1981 sind durch kontaminiertes Speiseöl nahezu 1,000 Menschen — meistens aus ärmeren Schichten herkommend — an schweren Vergiftungen gestorben und weitere tausend schwer erkrankt. Die Behörden haben nur zögerlich auf die größte Gesundheitskatastrophe in der spanischen Geschichte, das sog. síndrome tóxico, reagiert und das Strafverfahren gegen die verantwortlichen Händler erst nach langer Verzögerung, gegen die nachlässigen Beamten der Aufsichtsbehörden noch gar nicht eingeleitet. Die kaum aufklärbaren Wege der Vermarktung des vergifteten Öles machten es schwierig, die für die Opfer verantwortlichen Personen aufzufinden und ihre Schuld nachzuweisen. Der Autor, der als Vertreter der geschädigten Nebenkläger bzw. ihrer Familien das umfangreiche, noch nicht durch ein Urteil abgeschlossene Strafverfahren vor der audencia nacionál in Madrid mehrere Jahre aktiv begleitet hat, untersucht die rechtlichen und tatsächlichen Probleme einer kollektivrechtlichen Bewältigung des síndrome tóxico und macht Verbesserungsvorschläge, auch zur Opferentschädigung. Ein Postskrip berichtet über das nach Fertigstellung am 20. März gefällte Urteil ins Strafverfahren gegen die aceiteros.

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Ignacio de Uriarte Bofarull is a lawyer in Madrid and legal counsel to OCU (Organisación de los consumidores y usuarios). He has represented part of the victims as private attorney in the legal proceedings against the aceiteros. His address: Goya 99, Madrid — 9, Spain.     

Wage rigidity and capital mobility in an optimizing model of a small open economy

Summary This paper formulates an optimizing model of a small open economy with a representative (immortal) household, a firm and a government. The asset menu consists of domestic currency, non-traded bonds and traded bonds. There is a risk premium on traded bonds, which leads to deviations from perfect capital mobility and uncovered interest parity. Taxes are lump-sum, so that finance by bonds and by taxation are equivalent. The model allows for current-account and wealth dynamics. The model assumes either purchasing power parity or imperfect substitution between home and foreign goods and either labour market equilibrium, nominal wage rigidity or real wage rigidity. The steady-state effects of a fiscal contraction, a monetary disinflation and an increase in the world interest rate are discussed. The transient effects of these policies are analysed with the aid of a multiple shooting algorithm.We thank Gerard Staarink for implementing the multiple shooting algorithm used in section 4 and we thank Professors M. Fase and J. Pen for their constructive comments on a previous version of this paper. The paper is a shortened version of discussion paper No. 168 of the Centre for Economic Policy Research, London.     

Probability theory in fuzzy sample spaces

This paper tries to develop a neat and comprehensive probability theory for sample spaces where the events are fuzzy subsets of The investigations are focussed on the discussion how to equip those sample spaces with suitable -algebras and metrics. In the end we can point out a unified concept of random elements in the sample spaces under consideration which is linked with compatible metrics to express random errors. The result is supported by presenting a strong law of large numbers, a central limit theorem and a Glivenko-Cantelli theorem for these kinds of random elements, formulated simultaneously w.r.t. the selected metrics. As a by-product the line of reasoning, which is followed within the paper, enables us to generalize as well as to bring together already known results and concepts from literature.Acknowledgement. The author would like to thank the participants of the 23rd Linz Seminar on Fuzzy Set Theory for the intensive discussion of the paper. Especially he is indebted to Professors Diamond and Höhle whose remarks have helped to get deeper insights into the subject. Additionally, the author is grateful to one anonymous referee for careful reading and valuable proposals which have led to an improvement of the first draft.This paper was presented at the 23rd Linz Seminar on Fuzzy Set Theory, Linz, Austria, February 5–9, 2002.     

Environmental uncertainty, supply chain relationship quality and performance

Environmental uncertainty is a fact of life in today's supply chains. In this paper we develop a model of environmental uncertainty, supply chain (SC) relationship quality and SC performance. We use data from the electronics sector in Ireland to test our model. Our results provide mixed support for the model, with the moderating role of both demand and supply uncertainty being supported, but technological uncertainty not supported. We reflect on these findings and suggest a research agenda based on our results.     

Nash-equilibria in a heterogeneous oligopoly with fuzzy information

We consider a model of an oligopolistic market with heterogeneous firms and products where neither the cost nor the demand functions are common knowledge. Instead, each firm only has some vague ideas about the price strategies adopted by its competitors which is modelled by a fuzzy set. In analogy to the notion of an "equilibrium of actions and beliefs" we define and characterize a generalized Nash-equilibrium and show its existence under general conditions. Furthermore, the impact of the fuzzy information on the equilibrium outcome is analyzed by means of a comparative static analysis within a particular model framework.Received: 28 May 2002, Accepted: 25 December 2002, JEL Classification: D43, D80, L13We wish to thank Bernhard F. Arnold, the editor Murat Sertel , and two anonymous referees for helpful comments. Of course, we are responsible for all remaining errors.     

De produktiestructuur van Nederland in de periode 1950-1966

Summary In 1961 Arrow, Chenery, Minhas and Solow presented their C.E.S. production function, which was based on the relation between the real wage rate and the average labour productivity. They argued that, if the aggregate production function is continuous, lineair and homogeneous, then, with perfect competition and profit maximalization prevailing, the relation between the real wage rate and the average labour productivity is reflection of the production structure. This relation can, therefore, be used for specifying the production structure.In the present paper, the same line of thought is applied to the Dutch economy. Several hypotheses on the relation between wage rate and average labour productivity are tested. Statistically, it turns out that in the Dutch economy the elasticity of substitution between capital and labour is not a constant: it declines with increasing capital-labour ratio. Two statistically acceptable production equations that have this feature are presented.The efficiency parameter appearing as an integration constant in both production equations shows a decline: with labour productivity constant, the capital-labour ratio is falling over time. This means that the relation between labour productivity and capital-labour ratio shifts over time. Another outcome of this study is that technical progress is capitalaugmenting and that it brings about 50 percent of the growth in the labour productivity.De schrijvers zijn dank verschuldigd aan Prof. Dr. F. J. de Jong voor zijn stimulerende kritiek en aan de heren J. G. Althuis, F. J. van Bolhuis, J. D. Flikweert, H. Jager en B. S. Wilpstra, assistenten bij de afdeling Algemene Economie van de Economische Faculteit der Rijksuniversiteit te Groningen, voor hun bereidwillige medewerking aan dit onderzoek.     

Rent Seeking with Efforts and Bids

We introduce bids in a rent-seeking contest. Players compete for a prize. Apart from exerting lobbying efforts, they also submit a bid which is payable only if they win the prize. We show that our model has a unique Nash equilibrium in pure strategies, in which each active player submits the same bid, while the sum of all efforts equals that bid. In equilibrium there is underdissipation of rent.     

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.