Einzelbesprechungen

Ohne ZusammenfassungAus dem Italienischen übersetzt von M. St. Braun, WienAus dem Italienischen übersetzt von E. Allina, WienAus dem Russischen übersetzt von A. GerschenkronÜbersetzt von Paul Brüll, Wien.     

Structure and understanding: Some observations on current activities in the field of structural modeling

Structural modeling has been under study in recent years as a method for dealing with complex societal problems, and is growing in acceptance as a tool for understanding complex social phenomena. Structural models demonstrate the interactions of the separate elements of a system and their combined overall effect. Thus, the nature of the problem for which this method of analysis is appropriate is different from complex problems of the traditional disciplines which lend themselves to reductionist approaches. This is because complex policy problems of society cannot be “solved” with precise analysis. Kenneth Boulding suggests that there are two ways to cope with a complex policy problem, either to “slice” the problem into partial equilibrium sections or “squeeze” it by aggregating numerous variables into a single index or macho variable. Structural modeling is an approach which comes under the general strategy of squeezing the problem and is promising because of the ability to include a range of macro variables which provide insights about social change. The articles in this issue treat several interesting aspects of this approach. In this article we wish to recall for consideration a central purpose for developing such methods. We have taken a historical approach to indicate some of the roots of the concern for the effect of technological process on social change. Within this context, we discuss the nature of the contributions made by the articles in this issue and what promise the methods offer to addressing the historical concern.     

Does the evidence on corruption depend on how it is measured? Results from a cross-country study on microdata sets

While much of the existing literature on corruption looks at the effect of corruption on macro variables such as growth rates and income distribution, this study provides a departure by focussing on victims of corruption by using microdata to compare civilian and business corruption. This study finds that businesses face a stronger incidence of bribe demands than individuals. Though there are several differences between the determinants of the two forms of bribe victimization, there are also some similarities. Policies to combat corruption need to take into account both the differences and the similarities.     

Bargaining and separation costs in two-sided markets

A two-sided market is characterized by contract negotiations, bilateral exchanges between buyers and sellers. Separation costs endow trading partners with monopoly power, rendering this a market of bilateral monopolistic competition. Market equilibrium is defined by these negotiations, a matching of the two sides, and a set of prices; the costs of disagreement are endogenous. A bargaining strategy some players use is commitment to a position. Disagreements are possible and, contrary to the case of bilateral monopoly, these disagreements are not always inefficient.     

A forecasting model for the market of competitive products

The classic way of performing a market forecast for industrial products implies an econometric analysis of the historical data of consumption and their projections into the future. The present work illustrates a fresh approach to the problem; the demand for the product under study is evaluated in a mathematical model which takes into consideration the technological and commercial characteristics of this product and correlates it with competitive and substitutive products. Competitiveness is measured by assigning merit scores to the characteristics of the different products, and calculating the relevant “weights of importance” on the basis of the historical consumptions. Forecasts of consumption are made by estimating the future scores of the characteristics and extrapolating the weights of importance. An example of complete application of the model to the textile market in Italy is included.     

Section 401(k), 403(b) and 457(b) plans: who can do what?

This article examines the three main types of supplementary pension arrangements. It focuses on their origins and development, employer eligibility, deferral and contribution limits, funding arrangements and other technical requirements as they have been affected by recent developments.     

Existence of Sparsely Supported Correlated Equilibria

We show that every N-player K ₁ × ... × K _N game possesses a correlated equilibrium with at least zero entries. In particular, the largest N-player K × ... × K games with unique fully supported correlated equilibrium are two-player games. We thank an anonymous referee for most useful comments. The first author acknowledges financial support from Spanish Ministry of Science and Technology, grant SEJ2004-03619, and in form of a Ramón y Cajal fellowship. The second author acknowledges support by the PASCAL Network of Excellence under EC grant no.506778, as well as from Spanish Ministry of Science and Technology and FEDER, grant BMF2003-03324. Both authors also acknowledge financial support from BBVA grant “Aprender a jugar.”