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.

     

共同领导新模式

正对很多企业来说,成长的机会跨越不同的市场疆域,而且挑战组织内部的界限。要做到这一点,需要跨部门来制定整合的策略和行动。这意味着,企业迫切需要针对高层,引进全新的领导模式当企业改变商业模式,高管团队最好也跟着改变彼此的互动模式。灵活应变的企业里,各部门的主管应建立相互依赖的关系,激励相互扶持,并谨慎处理这些关系,以促进协同合作。成功企业的高管,通常     

THE CEO: A VISIBLE HAND IN WEALTH CREATION?

Commensurate with the growth of their pay packages and public visibility, the role of the CEO in the corporate value creation process has increased significantly in recent years. This article argues that sustained wealth creation in a corporation has three distinct elements. The first and most basic is the selection of the lines of business in which to operate; this element is probably the most visible manifestation of CEO action in large corporations today. The second element is the value creation model, which answers the question: How is this particular set of businesses expected to add value over and above the sum of the values of each business or asset category standing alone? The third element is the internal governance system, which establishes the corporate structure and administrative processes of the firm and, perhaps even more important, defines the corporate values that drive the strategic and operational priorities of the different business units. The authors suggest that the essence of the work of the CEO is to develop and maintain a balanced relationship among these three elements of wealth creation and to ensure that the relationship evolves in the face of changing circumstances. CEOs are inevitably faced with dilemmas in managing this process—in particular, the need to balance continuity and change and to maintain the integrity of short‐term performance disciplines while encouraging not only investment in growth opportunities (which can hurt near term performance), but also experimentation and collaboration among business units (which are difficult to measure and reward with most performance measurement and incentive schemes). Adding to the difficulties of managing such dilemmas, visibility and a strong public image are often thrust upon (if not sought by) CEOs, who must then determine how they can use that image to strengthen the commitment of their employees and investors.     

Separating small and big fish: The case of income tax evasion

This paper proposes to offer the taxpayer a choice of tax-enforcement schemes for self-selection. More specifically, the taxpayer should have the possibility of opting for the prevailing regime with a certain penalty on the evaded tax or for an alternative regime with a higher penalty on the evaded tax but a reduced tax rate. It is shown that this leads to a separation of taxpayers characterized by a relatively high degree of evasion (H-evaders) from taxpayers who evade only a relatively small amount of tax (L-evaders). Furthermore, the procedure is not self-defeating, it is effectively possible to direct the efforts of auditing towards the H-evaders. At the end of the game the L-evaders experience a welfare gain, the H-evaders are induced to reduce their evasion activities and the government can expect higher yields.We wish to thank Johann K. Brunner and two anonymous referees for many helpful comments.     

Versicherungsmedizinische Risikobeurteilung von pathologischen Leberwerten und aktuellen Entwicklungen bei der chronischen Hepatitis

Alcoholic liver disease, non alcoholic fatty liver and chronic viral hepatitis have a high prevalence in the German population. They are associated with significantly increased occupational disability and mortality. Elevated levels of GGT or ALT can be found in about 10 % of the general population. Attempts to identify an underlying diagnosis often remain unsuccessful. In selected cases CDT can be helpful to confirm or rule out suspected alcohol-abuse. Recent studies showed that non alcoholic steatohepatitis (NASH) is a potentially severe complication of diabetes and its metabolic precursors. Treatment options for chronic viral hepatitis get more and more sophisticated, but the rates of sustained cure are still unsatisfactory, especially in hepatitis B with negative HBe-antigen and the hepatitis C genotypes 1, 4 and 5. Life long suppression of HBV replication by nucleoside analogues seems to prevent liver cirrhosis, but may become a great burden on health costs. The risk assessment of HBV carriers and of patients with successfully treated viral hepatitis should rely on the expertise of experienced physicians.     

The structure of consumer preferences,Federal Republic of Germany, 1950–1973

Summary The objective of this paper is to analyze the structure of consumer preferences and changes in preferences over time. Consumer preferences are represented by an indirect translog utility function with time-varying preferences that is quadratic in the logarithms of its arguments. We consider a system of demand functions associated with parameter restrictions consistent with the theory. We characterize groupwise separability and groupwise homotheticity of preferences and derive for each set of restrictions on preferences parametric restrictions on the corresponding system of demand functions. Empirical results of the tests, based on time series data for FRG consumption expenditures on three commodity groups — durables, non-durables, and energy — are presented.