The Stochastic Behavior of Commodity Prices: Implications for Valuation and Hedging

In this article we compare three models of the stochastic behavior of commodity prices that take into account mean reversion, in terms of their ability to price existing futures contracts, and their implication with respect to the valuation of other financial and real assets. The first model is a simple one-factor model in which the logarithm of the spot price of the commodity is assumed to follow a mean reverting process. The second model takes into account a second stochastic factor, the convenience yield of the commodity, which is assumed to follow a mean reverting process. Finally, the third model also includes stochastic interest rates. The Kalman filter methodology is used to estimate the parameters of the three models for two commercial commodities, copper and oil, and one precious metal, gold. The analysis reveals strong mean reversion in the commercial commodity prices. Using the estimated parameters, we analyze the implications of the models for the term structure of futures prices and volatilities beyond the observed contracts, and for hedging contracts for future delivery. Finally, we analyze the implications of the models for capital budgeting decisions.     

Working-time reduction and employment: experiences in Europe and economic policy recommendations

The paper seeks to evaluate the evidence on the employment effectsof the collective working-time reductions in Europe over thepast 20 years. While theoretical analyses produce contradictoryassessments, most empirical studies show positive employmenteffects but take insufficient account of these conditions underwhich the reductions in working time were implemented. Theseconditions for the success of collective working-time reductionsinclude an active training policy designed to minimise skillshortages in the labour market, the modernisation of work organisation,wage increases in conjunction with productivity gains and amore equal income distribution.     

Linking of U.S. monetary policy and exchange rates to world soybean markets

The linkage between macroeconomic policies and agricultural commodity trade has become an important research issue of agricultural economists. This paper investigates the macroeconomic linkage of soybean trade competition between the exporting countries of the United States, Brazil, and Argentina in the EC-12 and Japan import markets. It is argued that U.S. monetary growth may have important impacts on the competitive position of U.S. soybean exports through exchange rates. Two relationships are investigated: (a) the effects of U.S. monetary growth on the agricultural trade weighted exchange rates, and (b) the responsiveness of agricultural commodity prices and U.S. exports to exchange rate movements. Results indicate that a weak dollar increases imports of soybeans and soymeal significantly which serves to increase the equilibrium world price and increase both U.S. and Brazil/Argentina exports in the long run. However, during periods of more expansionary U.S. monetary policy there is little evidence of significant increases in market share position for U.S. soybeans and soymeal in world markets.     

Economic design of one-sided screening procedures based on a correlated variable with all parameters unknown

Summary Economic design of one-sided screening procedures for improving outgoing product quality based on a screening variable is considered for the case with all parameters unknown. It is assumed that the performance and screening variables are jointly normally distributed and that costs are incurred by screening inspection, acceptance of an imperfect item, and disposition of a rejected one. A method for finding optimal cutoff value based on the predictive distribution is presented.     

A conceptual framework of anonymity in Group Support Systems

As the development and use of automated systems for collaborative work grows, the need for a better understanding of these systems becomes more important. Our focus is on one type of system, a Group Support System (GSS) and, in particular, on one important aspect of a GSS—anonymity. A conceptual framework for the study of anonymity in a GSS is presented, which describes the general classes of variables and their relationships. These variables include the factors that influence anonymity in a GSS, types of anonymity, and the effects of anonymity on a message sender, receiver, group process, and outcome. Each of these variables is discussed with working propositions presented for important group process and outcome measures. The objectives of this article are to highlight the importance and complexity of anonymity, to act as a guide for empirical investigations of anonymity, and to influence future GSS development and use.     

Issues in the estimation and application of latent structure models of choice

Our paper provides a brief review and summary of issues and advances in the use of latent structure and other finite mixture models in the analysis of choice data. Focus is directed to three primary areas: (1) estimation and computational issues, (2) specification and interpretation issues, and (3) future research issues. We comment on what latent structure models have promised, what has been, to date, delivered, and what we should look forward to in the future.