OPTIMAL SOCCER STRATEGIES

This paper examines soccer teams' strategic choices about the extent of offense/defense to adopt in competing with other teams. The sample is European Champions League group stage matches played between 1997–1998 and 2009–2010. We begin by developing a characterization of teams' strategies (extent of offense or defense) using principal component analysis. This is used to estimate the relationship between a team's probabilities of scoring and conceding goals and its chosen strategy. Knowing that relationship, it is then possible to derive a team's optimal strategy, and to study how this varies in different situations (such as playing at home or away). A comparison between optimal and actual strategy reveals that teams appear to adopt more defensive strategies than is optimal. A notable feature of our study is that we model a team as choosing a strategy at the start of each match and also at half time, thereby incorporating a dynamic element. (JEL C23, C72, L83, Z00)     

A heterarchical generic discrete manufacturing simulation model and its application in a world class manufacturing environment

Current factory design and evaluation is very primitive. Factory components are designed in many cases independently. Product and process design are not well integrated. An encompassing framework is needed for iterating through a series of total factory designs, searching for optimal performance. In addition, a vehicle is needed for predicting the performance of a proposed advanced manufacturing system, so that engineers may have a sound means for evaluating such proposals. A heterarchical discrete manufacturing SIMNET II simulation model (SIMCELLS) was developed as a comprehensive methodology for designing and evaluating discrete manufacturing systems. SIMCELLS allows manufacturing systems engineers to experiment with alternative system structures and control strategies while seeking that combination of design features that will produce the desired overall system performance. The model in combination with a modernization programme is enabling a firm to successfully manufacture and sell trucks meeting international standards. The SIMNET II model     

A Kernel Variogram Estimator for Clustered Data

Abstract.  The variogram provides an important method for measuring the dependence of attribute values between spatial locations. Suppose that the nature of the sampling process leads to the presence of clustered data; it would be advisable to use a variogram estimator that aims to adjust for clustering of samples. In this setting, the use of a non-parametric weighted estimator, obtained by considering an inverse weight to a given neighbourhood density combined with the kernel method, seems to have a satisfactory behaviour in practice. This paper pursues a theoretical study of the cluster robust estimator, by proving that it is asymptotically unbiased as well as consistent and by providing criteria for selection of the bandwidth parameter and the neighbourhood radius. Numerical studies are also included to illustrate the performance of the considered estimator and the suggested approaches.     

NONLINEAR PRICING STRATEGIES AND COMPETITIVE CONDITIONS IN THE AIRLINE INDUSTRY

This paper empirically examines the effect of competitive conditions on nonlinear pricing strategies in the airline industry. We use a unique data set to analyze the impact of concentration and the competitive pressures generated by Southwest and other low cost carriers on the relative prices within a menu of fares. The menu orders tickets by quality based upon cabin and ticket restrictions. We analyze the ratio of fares charged for various qualities within the menu to the fares charged for the lowest quality nonrefundable, restricted tickets. We observe a fare compression for only the highest fares on only the most concentrated (i.e., monopoly) routes. This result is something of a puzzle given a monopolist's market power. We find, however, that actual and potential competition from Southwest reduces low end fares and generally leads to substantial fare compression throughout the fare menu. (JEL L11, L93)     

THE UNEMPLOYMENT VOLATILITY PUZZLE: THE ROLE OF MATCHING COSTS REVISITED

Pissarides has argued that the standard search model with sunk fixed matching costs increases unemployment volatility without introducing an unrealistic response of wages of new matches to productivity shocks. We revise the role of matching costs and show that when these costs are not sunk and, therefore, can be partially passed on to new hired workers in the form of lower wages, the amplification mechanism of fixed matching costs is considerably reduced. Finally, we observe that an empirical reasonable share of sunk costs is not able to match the volatility of unemployment without introducing unrealistic sensitivity to unemployment benefits. (JEL E32, J32, J64)     

Rethinking the Concept of Sustainability

The role of business ethics in developing more sustainable societies is crucial, but we first have to review the concept of sustainability itself and its ethical roots. The objective of this work is to rethink the current concept of sustainability by providing it with a sound universalistic ethical rationale. We propose that ethics is the key by which disputes and conflicts among the economic, social, and environmental domains can and ought to be resolved. This work argues that if we fail to recognize the essential ethical grounding of sustainability, or if we take it for granted, then sustainability can easily lose its way and can end up unjustified.     

EVALUATING THE ECONOMIC COST OF ENVIRONMENTAL MEASURES IN PLANTATION HARVESTING THROUGH THE USE OF MATHEMATICAL MODELS

An important issue being discussed for Chilean pine plantation policies is the application of environmental protection measures when managing its timber areas. Typical measures, already in place in more developed countries, include imposing riparian strips and protecting fragile soils from the use of heavy machinery. While environmental protection measures have been considered vital for decades, so far there has been almost no attempt to quantify both the benefits and costs of these measures. This paper attempts to measure the costs associated with the main measures which can help both the forestry firms and the government evaluate the cost impact of the new environmental protection regulations being studied. The analysis for different environmental scenarios is carried out by modifying a mixed integer LP, currently used for tactical planning by one forestry firm.