Journal Article

Note e dicussioni

LUINI, LUIGI, SCHIANCHI, AUGUSTO, GRASSO, MARCO, PAREGLIO, STEFANO, MANGANI, ANDREA

2002

Overview

Modern companies adopt the brand extension strategies in order to maximize their brand equity, and the economists' interest about these practices has recently grown. The studies of Industrial Organization examine the relevant aspects of the brand extension: whether or not to extend, the timing of the extension, the markets involved, and the spillover effects. This paper discusses the main findings and the issues that need further research. This paper offers a critical review of natural resource valuation and points out the role of economic valuation in EU policy-making. First of all, we specify the meaning of the economic value of environmental amenities and illustrate the most reliable and often used economic valuation techniques, and their major weaknesses. We then point out the normative significance of environmental valuation in the evolution of the EU environmental consciousness, and distinguish between its different applications. According to this framework, we critically review the studies carried out in the last few years (1998-2001) by the European Commission DG Environment, which are both methodological and application-oriented. Furthermore, we carry out a restricted survey on research in Europe. Our analysis makes clear that the diffusion of environmental valuation in Europe is unsatisfactory and that decision-makers distrust is still strong. In this paper, we solve a general problem of optimizing a portfolio in a futures markets framework, originally considered by Lintner in a very simplified scheme. We extend the previous work of Galluccio, Bouchaud and Potters. We allow for long buying/short selling of a relatively large number of assets, assuming a fixed level of margin requirement. Because of non-linearity in the constraint, we derive a multiple equilibrium solution, in a size exponential respect to the number of assets. That means that we cannot obtain the unique efficiency frontier, but many of them and each one is related to different levels of risk. Such a problem is analogous to that of finding the ground state in longranged Ising spin glass with external field. In order to get the best portfolio (i.e. along the best efficiency frontier), we have to implement a two-step procedure, doing the complete enumeration of all local minima. We suggest defining this procedure as complex rationality.

• Publisher: Societa Cattolica Italiana per gli Studi Scientifici