Consistency of elementwise-weighted total least squares estimator in a multivariate errors-in-variables model <Emphasis Type="Bold">AX=B</Emphasis>

A multivariate measurement error model AXB is considered. The errors in [A,B] are rowwise independent, but within each row the errors may be correlated. Some of the columns are observed without errors, and in addition the error covariance matrices may differ from row to row. The total covariance structure of the errors is supposed to be known up to a scalar factor. The fully weighted total least squares estimator of X is studied, which in the case of normal errors coincides with the maximum likelihood estimator. We give mild conditions for weak and strong consistency of the estimator, when the number of rows in A increases. The results generalize the conditions of Gallo given for a univariate homoscedastic model (where B is a vector), and extend the conditions of Gleser given for the multivariate homoscedastic model. We derive the objective function for the estimator and propose an iteratively reweighted numerical procedure.Acknowledgements.A. Kukush is supported by a postdoctoral research fellowship of the Belgian office for Scientific, Technical and Cultural Affairs, promoting Scientific and Technical Collaboration with Central and Eastern Europe. S. Van Huffel is a full professor with the Katholieke Universiteit Leuven. This paper presents research results of the Belgian Programme on Interuniversity Poles of Attraction (IUAP Phase V-22), initiated by the Belgian State, Prime Ministers Office-Federal Office for Scientific, Technical and Cultural Affairs, of the Concerted Research Action (GOA) projects of the Flemish Government MEFISTO-666 (Mathematical Engineering for Information and Communication Systems Technology), of the IDO/99/03 project (K.U. Leuven) Predictive computer models for medical classification problems using patient data and expert knowledge, of the FWO projects G.0200.00, G.0078.01 and G.0270.02. The scientific responsibility is assumed by its authors. The authors would like to thank Maria Luisa Rastello and Amedeo Premoli for bringing the EW-TLS problem to their attention. The authors are grateful to two anonymous referees for the valuable comments.     

Hans Mayer — Leben und Werk

Ohne Zusammenfassung     

Sraffa's legacy

This review essay of Critical Essays on Piero Sraffa's Legacyin economics situates Sraffa's work in relation to the Marshalliantradition and neo-Walrasian general equilibrium theory, andreviews the current state of debate between adherents of thesetraditions on the role of demand, returns to scale, capitaltheory and policy analysis. Other issues considered includethe corn model, Sraffa's critique of Hayek, and the extensionof the capital theory critique to the intertemporal equilibriummodel.     

The Impact of Surplus Distribution on the Risk Exposure of With Profit Life Insurance Policies Including Interest Rate Guarantees

This article analyzes the numerical impact of different surplus distribution mechanisms on the risk exposure of a life insurance company selling with profit life insurance policies with a cliquet‐style interest rate guarantee. Three representative companies are considered, each using a different type of surplus distribution: a mechanism, where the guaranteed interest rate also applies to surplus that has been credited in the past, a slightly less restrictive type in which a guaranteed rate of interest of 0 percent applies to past surplus, and a third mechanism that allows for the company to use former surplus in order to compensate for underperformance in “bad” years. Although at the outset all contracts offer the same guaranteed benefit at maturity, a distribution mechanism of the third type yields preferable results with respect to the considered risk measure. In particular, throughout the analysis, our representative company 3 faces ceteris paribus a significantly lower shortfall risk than the other two companies. Offering “strong” guarantees puts companies at a significant competitive disadvantage relative to insurers providing only the third type of surplus distribution mechanism.     

Rare events and annuity market participation

We investigate whether a rare event (like the default of the annuity provider) can explain the annuity market participation puzzle. High risk aversion is needed to change behavior in the presence of such a disastrous shock but higher risk aversion also makes annuities more valuable. Therefore, these rare events are unlikely candidates to explain the low take-up of voluntary annuities: the conclusion is robust to disentangling risk aversion from intertemporal substitution and to allowing portfolio investment in a stock market index.     

Market Responses to Buy Recommendations Issued by Personal Finance Magazines: Effects of Information, Price-Pressure, and Company Characteristics

This paper analyzes explicit buy recommendations for stockspublished by German Personal Finance Magazines from 1995 to2003. These recommendations earn significant abnormal returnsof 2.58% within the five days around the publication day. Boththe price-pressure hypothesis and the information hypothesiscan be confirmed by our data. The price-pressure effect is mostevident for small stocks and glamour stocks. However, whereasthe initial price reaction to small stocks is additionally drivenby permanent information value, this does not hold true forglamour stocks. In contrast, value stocks are associated withhigh cumulative abnormal returns that are solely driven by informationvalue.     

Valuation of synthetic CDOs

In this paper, we consider the valuation of a synthetic collateralized debt obligation (CDO), a pool of underlying credit risky securities, “partitioned” into several tranches, each of which absorbs losses in accordance with its size and seniority. We derive a closed-form solution for credit spreads of the tranches of homogeneous pools and find an approximation for the credit spreads of inhomogeneous pools. The method leads to an accurate estimation of the credit spreads of synthetic CDOs and can be used in risk management applications.