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.     

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.     

Characteristics of agricultural input package users in communal clubs serviced by Acat in KwaZulu: A note

Characteristics of communal club members who use input packages are studied using a survey of communal clubs serviced by Africa Co‐operative Action Trust (Acat) in KwaZulu during 1989. Discriminant analysis shows that full input package adopters tend to belong to older clubs, have less formal savings and receive more visits each year from KwaZulu Department of Agriculture (KDA) extension officers. They also have a greater proportion of land under sugar‐cane, larger farm sizes and a higher rand monetary value of livestock.

Members of older clubs benefit from greater club experience in ordering inputs and liquidity for securing discounts on bulk orders. Clubs also enable scarce KDA extension manpower resources to be used more effectively by focusing extension efforts on groups rather than individual farmers. Sugar‐cane production probably indicates member willingness to innovate and the availability of funds to buy complete input packages for other crops. Increased access to land promotes input package adoption which can raise agricultural productivity. Development of institutional arrangements for a land rental market in KwaZulu should be considered. Higher monetary values of livestock reflect Increased ability to bear risk associated with technology adoption and that adopters have the means to purchase input packages     

There is relevance in the classroom: Analysis of present methods of teaching business ethics

In 1988 the Journal of Business Ethics published a paper by David Mathison entitled Business Ethics Cases and Decision Models: A Call for Relevancy in the Classroom. Mathison argued that the present methods of teaching business ethics may be inappropriate for MBA students. He believes that faculty are teaching at one decision-making level and that students are and will be functioning on another (lower) level. The purpose of this paper is to respond to Mathison's arguments and offer support for the present methods and materials used to teach Master level ethics classes. The support includes suggested class discussion ideas and assignments.Victoria K. Strong is a graduate student at Bentley College. She returned to school to pursue a Master of Science in Accountancy after working in the engineering profession for 12 years. She received her B.S. in Mechanical Engineering in 1984. Her business experience includes positions as Mechanical Design Engineer and Unit Supervisor of an engineering development laboratory. Alan N. Hoffman is an Associate Professor of Management at Bentley College. He received his DBA from Indiana University. Dr. Hoffman's writing has been published in the Academy of Management Journal and Human Relations.The authors would like to thank Carolyn Colt and the entire spring 1988 MG520-class for their valuable contributions.     

Regional, national, and spatially explicit scenarios of demographic and economic change based on SRES

We report here spatially explicit scenario interpretations for population and economic activity (GDP) for the time period 1990 to 2100 based on three scenarios (A2, B1, and B2) from the IPCC Special Report on Emissions Scenarios (SRES). At the highest degree of spatial detail, the scenario indicators are calculated at a 0.5 by 0.5 degree resolution. All three scenarios follow the qualitative scenario characteristics, as outlined in the original SRES scenarios. Two scenarios (B1 and B2) also follow (with minor adjustments due to scenario improvements) the original SRES quantifications at the level of 4 and 11 world regions respectively. The quantification of the original SRES A2 scenario has been revised to reflect recent changing perceptions on the demographic outlook of world population growth. In this revised “high population growth” scenario, A2r world population reaches some 12 billion by 2100 (as opposed to some 15 billion in the original SRES A2 scenario) and is characterized by a “delayed fertility transition” that is also mirrored in a delayed (economic) development catch-up, resulting in an initially stagnating and subsequently only very slow reduction in income disparities. The spatially explicit scenario interpretation proceeds via two steps. Through a combination of decomposition and optimization methods, world regional scenario results are first disaggregated to the level of 185 countries. In a subsequent second step, national results are further disaggregated to a grid cell level, taking urbanization and regional (rural–urban) income disparities explicitly into account. A distinguishing feature of the spatially explicit scenario results reported here is that both methodologies, as well as numerical assumptions underlying the “downscaling” exercise, are scenario-dependent, leading to distinctly different spatial patterns of population and economic activities across the three scenarios examined.