SIMULATION AND THE CAPITAL ASSET PRICING MODEL: A COMMENT*

This paper challenges Lewellen and Long's contention that a Hertz-type simulation generates irrelevant data for the evaluation of capital expenditure opportunities. The conclusion is reached that an estimate of an asset's “own risk” may be a vital first step in estimating its covariance properties with the market index. A method of incorporating the information generated by simulation into the capital asset pricing model is also provided.     

论停滞与失败--思想意识形态与历史:两个初步的问题(之一)

理学作为一种思想体系受到朝廷的推崇,并作为科举考试的组成部分。在20世纪,对理学的看法发生了分歧。有人认为理学是智识与科学进步的障碍,中国要想走向现代化就必须摆脱理学。关于中国在12世纪后进入长时期停滞的看法,历史学界一般都不赞成了,但读者的这种看法还比较强烈。对于中国历史的一些基本特征的认识需要重新检验,比如中国文化不是只有一个起源;中国并非与外界隔离并拒绝外界影响;中国的政治体制不是绝对独裁;中国文化并没有一个纯正的“正统”或“道统”(orthodox);中国人并非没有自主的完整实体的“自我”观念。学者在实际研究中往往把中国当作一个实体民族或一个连续不断的文明体,这种观念并不太准确,实际是误解了China的原意。     

Japanese marketing strategies in the United Kingdom

This article is based on a study which examined hypotheses about Japanese marketing using a matched sample of British companies and their major Japanese competitors. Japanese subsidiaries in Britain were shown to be much more marketing-oriented, more responsive to strategic opportunities, and more single-minded in their pursuit of market share. Organizationally, there were few differences between the two groups. The Japanese subsidiaries, however, were more inclined to use product or market-based divisions and continuous, informal planning and control procedures. The result is that managerial focus and responsibility are centred upon overall product-market rather than financial or production performance, with continuous feedback facilitating rapid adaptation and implementation of marketing plans and strategy.     

Changes in HIV/AIDS knowledge and testing behavior in Africa: how much and for whom?

Demographic and Health Survey data from nine African countries make it clear that HIV/AIDS prevention knowledge has been increasing. Still, in many cases, fewer than half of adult respondents can identify specific prevention behaviors. Knowledge is lowest in rural areas and among women. HIV testing generally remains rare but is highly variable across countries, likely reflecting differences in the supply of testing services. In most cases, schooling and wealth impacts on prevention knowledge have either been stable or have increased; hence, in the majority of contexts, initial disparities in knowledge by education and wealth levels have persisted or widened.

Importance of interpolation when constructing double-bootstrap confidence intervals

We show that, in the context of double-bootstrap confidence intervals, linear interpolation at the second level of the double bootstrap can reduce the simulation error component of coverage error by an order of magnitude. Intervals that are indistinguishable in terms of coverage error with theoretical, infinite simulation, double-bootstrap confidence intervals may be obtained at substantially less computational expense than by using the standard Monte Carlo approximation method. The intervals retain the simplicity of uniform bootstrap sampling and require no special analysis or computational techniques. Interpolation at the first level of the double bootstrap is shown to have a relatively minor effect on the simulation error.     

Penalized Pseudolikelihood Inference in Spatial Interaction Models with Covariates

Given spatially located observed random variables ( x , z = {( x _i , z _i )} _i , we propose a new method for non-parametric estimation of the potential functions of a Markov random field p ( x | z ), based on a roughness penalty approach. The new estimator maximizes the penalized log-pseudolikelihood function and is a natural cubic spline. The calculations involved do not rely on Monte Carlo simulation. We suggest the use of B-splines to stabilize the numerical procedure. An application in Bayesian image reconstruction is described.     

Medical Students' Attitudes and Opinions About Human Sexual Behaviour

In their professional capacities doctors are often confronted with clients who present with psycho-sexual problems. At the present time Australian medical students are provided with very little instruction in the areas of human sexual behaviour. This paper examines the attitudes and amount of information possessed by a cohort of second year medical students compared with groups of first and fifth year students; these attitudes and levels of information are then related to students' sex, religious affiliation, strength of religious conviction, where this is seen to be relevant. It is shown that some areas of ignorance exist. The paper concludes by outlining some aspects relevant to courses in human sexual behaviour.     

TWO-PIECE VON NEUMANN-MORGENSTERN UTILITY FUNCTIONS*

Thirty empirically assessed utility functions on changes in wealth or return on investment were examined for general features and susceptability to fits by linear, power, and exponential functions. Separate fits were made to below-target data and above-target data. The usual “target” was the no-change point. The majority of below-target functions were risk seeking; the majority of above-target functions were risk averse; and the most common composite shape was convex-concave, or risk seeking in losses and risk averse in gains. The least common composite was concave-concave. Below-target utility was generally steeper than above-target utility with a median below-to-above slope ratio of about 4.8. The power and exponential fits were substantially better than the linear fits. Power functions gave the best fits in the majority of convex below-target and concave above-target cases, and exponential functions gave the best fits in the majority of concave below-target and convex above-target cases. Several implications of these results for decision making under risk are mentioned.     

Population monotonic path schemes for simple games

A path scheme for a game is composed of a path, i.e., a sequence of coalitions that is formed during the coalition formation process and a scheme, i.e., a payoff vector for each coalition in the path. A path scheme is called population monotonic if a player’s payoff does not decrease as the path coalition grows. In this study, we focus on Shapley path schemes of simple games in which for every path coalition the Shapley value of the associated subgame provides the allocation at hand. Obviously, each Shapley path scheme of a game is population monotonic if and only if the Shapley allocation scheme of the game is population monotonic in the sense of Sprumont (Games Econ Behav 2:378–394, 1990). We prove that a simple game allows for population monotonic Shapley path schemes if and only if the game is balanced. Moreover, the Shapley path scheme of a specific path is population monotonic if and only if the first winning coalition that is formed along the path contains every minimal winning coalition. We also show that each Shapley path scheme of a simple game is population monotonic if and only if the set of veto players of the game is a winning coalition. Extensions of these results to other efficient probabilistic values are discussed.