Optimising a Probabilistic Model of the Development of Play in Soccer

We present a probabilistic model based on the one developed by Hernández Mendo and Anguera (Revista de Psicologíca Social, 16(1), 71–93, 2001). Here we have tried to break down the interaction contexts that the opposing teams are able to generate and transform during the game. We are aware that a given player or team does not produce consistent behaviour in similar situations. However, a degree of uncertainty is assumed to exist regarding whether the results obtained are a specific function of the analysis used. In order to carry out this research a category system which optimized that used in the previous model was developed. This system should enable the interaction between teams to be observed within the actual play of a soccer game. A lag sequential analysis was performed on the basis of a coding of the behavioural flow. After describing the behavioural patterns obtained a probabilistic model of the development of play in soccer is proposed.     

Zur Entscheidung y>y0 aufgrund der Messung einer korrelierten Variablen

Zusammenfassung Es wird eine optimale Strategie im Sinne des minimalen erwarteten Verlustes für die beiden Entscheidungeny>y _o undyy _o aufgrund der Messungen einer mitY positiv korrelierten, einfacher und/oder billiger zugänglichen ZufallsvariablenX abgeleitet. Dabei wird angenommen, daßX undY nach einer bivariaten Normalverteilung mit bekannten Parametern verteilt sind und die Entscheidungyy _o getroffen wird, wennx größer ist als ein zu bestimmendesx _o, und die Entscheidungy>y _o, wennx gleich oder kleiner als diesesx _o ist. Für die Bestimmung des optimalenx _o werden zunächst die Kosten für die beiden Fehlentscheidungen jeweils als konstant vorausgesetzt, in einem weiteren Ansatz wird jedoch für die Mißklassifikationyy _o eine mity exponentiell wachsende Risikofunktion angenommen. Um die relative Häufigkeit der zu erwartenden Fehlklassifikationen abschätzen zu können, wird schließlich die bedingte WahrscheinlichkeitP(x>x _o,y) errechnet.

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Summary An optimal strategy, with minimum expected risk, for the decisionsy>y _o oryy _o is constructed on the basis of the measurement of a variableX, which is positively correlated withY and can be measured more easily and/or with smaller expense. A bivariate normal distribution with known parameters is assumed forX andY. For the observationsx a limitx _o is aimed at, so that the decisionsy>y _o oryy _o are taken ifx>x orxx _o respectively. Optimal values ofx _o are first calculated under the assumption of constant losses for the two misclassifications (x>x _o ifyy _o andxx _o ify>y _o). In a further approach the loss for a wrong decisionyy _o is assumed to increase exponentially withy. Finally the conditional probabilityP (x>x _o\y) is calculated to get an assessment of the relative frequencies of wrong decisions to be expected.

     

A General Method of Deriving the Inefficiencies of Banks from a Profit Function

This article develops a new method of estimating inefficiencies in joint production and shows that unlike the approaches utilized in the previous studies of inefficiency, this method maintains a consistent relationship between the error term of a profit function and the error terms of its price derivatives. A useful by-product of the method is a proof of a Hotelling-like lemma that relates stochastic input demand and output supply functions to stochastic profit functions. While the previous studies fit a single frontier to data on all firms, this paper estimates a frontier unique to every observed firm to allow each one to have a different potential of achieving maximal levels of profit. The new method is applied in the analysis of annual data, 1984–1989, for U.S. commercial banks. Both the analytical and numerical results of the paper show that the residual that the previous studies attribute to inefficiency includes the effects of excluded variables and of inaccuracies in the specified functional forms. Once accurate estimates of these effects are subtracted from the residual, the distortions in the measured inefficiencies should be considerably reduced. Consequently, this article considers how such estimates might be obtained.     

Dating Business-Cycle turning points

This paper presents a logit model for dating business-cycle turning points. The regressors are monthly series from the Business Cycle Indicators database of the Conference Board. Dividing the sample period into a subset for model initialization (1959∶9–1970∶12) and a subset for testing (1971∶1–2003∶12) yields a chronology that is nearly identical to that established by the National Bureau of Economic Research (NBER). However, the recognition lag is less than four months, in contrast to an average of more than eleven months for the official chronology. (JEL E320) The author is grateful for comments by an anonymous referee.     

Dynamics of fertility and labour force participation of Canadian women in 1971 and 1981: a cohort approach

The authors analyze the relationship between labor force participation and fertility in Canada using data from the Public Use Sample Tapes from the 1971 and 1981 censuses. Factors considered include age, religion, educational status, and marital status. The authors conclude that "labour force participation of women seems to have less influence on fertility compared to [the] fertility effect on labour force participation."     

Using a customer-Level marketing strategy to enhance firm performance: A review of theoretical and empirical evidence

It is becoming increasingly apparent from the literature that marketers need to consider customer-level information when they generate a marketing strategy for the firm. In this article, the authors develop a customer-focused framework that uses a marketing strategy with an overall objective of maximized financial performance. This strategy is driven by seven customer-level marketing tactics and shows how actual customer data can be used to generate an actionable marketing strategy leading to optimal levels of profitability, customer equity, and shareholder value. In addition, the authors discuss a successful implementation of this strategy for several business-to-business and business-to-consumer firms and offer insights as to how to customize an implementation strategy for any firm, along with presenting potential challenges a firm may encounter during the implementation process. Several suggestions for future research are offered to explore and harness this newly available evidence. V. Kumar (VK) (vk@business.uconn.edu) is the ING Chair Professor of Marketing and the executive director of the ING Center for Financial Services at the University of Connecticut. He spends his time by transferring his knowledge (however little it may be) to his two daughters about customer lifetime value, diffusion models, forecasting sales and market share, retailing, and marketing strategy. J. Andrew Petersen (apetersen@business.uconn.edu) is a doctoral candidate in marketing at the University of Connecticut. His research interests include customer lifetime value, word-of-mouth effects, and customer-level marketing strategy. His research has been published inMarketing Research Magazine and theJournal of the Academy of Marketing Science.     

Drivers and implications of entrepreneurial orientation for academic spin-offs

International Entrepreneurship and Management Journal - This paper has been designed with a dual goal. On the one hand, the paper aims to examine the role of management teams, industry agents, and...