Parametric discounting

A parametric approach to the problem of selection from amongst alternative investment opportunities is considered in a discounted cash flow framework. The approach employs differential cash flows, an uncertain planning horizon and a nested approach to composing cash flow parameters. This promotes consistent treatment of alternative investments, clarifies the effects of uncertainty, avoids some of the defects of internal rate of return and payback period criteria and allows direct comparison of best and next best options as primal and dual versions of the same model. Net present value, internal rate of return, annual average cost or payback period assessments may be selected post analysis. A domestic wall insulation example is used for illustrative purposes. This example is related to the hydroelectric power development decision which gave rise to the approach.     

Consideration of Background Exposures in the Management of Hazardous Waste Sites: A New Approach to Risk Assessment

The current approach to health risk assessment of toxic waste sites in the U.S. may lead to considerable expenditure of resources without any meaningful reduction in population exposure. Risk assessment methods used generally ignore background exposures and consider only incremental risk estimates for maximally exposed individuals. Such risk estimates do not address true public health risks to which background exposures also contribute. The purpose of this paper is to recommend a new approach to risk assessment and risk management concerning toxic waste sites. Under this new approach, which we have called public health risk assessment, chemical substances would be classified into a level of concern based on the potential health risks associated with typical national and regional background exposures. Site assessment would then be based on the level of concern for the particular pollutants involved and the potential contribution of site contaminants to typical background human exposures. While various problems can be foreseen with this approach, the key advantage is that resources would be allocated to reduce the most important sources of human exposure, and site remediation decisions could be simplified by focussing on exposure assessment rather than questionable risk extrapolations.     

WHY FAMILY THERAPY SHOULD GO BEYOND HOMEOSTASIS: A KUHNIAN REPLY TO ARIEL,CAREL AND TYANO

The thesis of “Beyond Homeostasis” is (a) that the discourse of family therapists unquestionably shows that family therapists have tended to see homeostasis as a trait of families; and (b) that such a view of homeostasis is inconsistent with the systemic paradigm. Therefore, family therapy should go beyond such an understanding of homeostasis. Ariel et al. may have failed to grasp this argument; they have certainly chosen to ignore it. Ariel et al. have provided a logical empiricist explication of the nonsystemic version of homeostasis which is portrayed in the discourse of family therapists. I still argue that family therapy should go beyond such an understanding of homeostasis.     

《林四娘》故事源流补考

林四娘的故事在康熙年间盛传一时，新发现的陈奕禧作品《林四娘小传》与蒲松龄、王士棋、李澄中等山东作家的记载相比，差距较大，与林云铭记述的故事更接近。若想了解这个有关青州衡王府宫人故事的文化背景，应该关注与她的名字密切联系的陈宝钥。陈宝钥是福建晋江人，曾参加了南明抗清斗争，又是一位多产的诗人。林四娘应该是陈宝钥部署的代言人，陈宝钥用自己和林四娘的唱和来抒发他的亡国之思。