Estimating Probabilities Relevant to Calculating Relative Risk-Corrected Returns of Alternative Portfolios

In making all-or-none choices between alternative securities, Samuelson (1997b) suggested that investors of different risk-aversion should calculate from past samples of those securities their relevant Harmonic Means, or Geometric means, or other associative means representative of their respective degrees of relative-risk-aversion. Here it is shown how this learning procedure can be improved upon when you have prior knowledge that the securities have log-Normal distributions. Classical estimation theory, concerning consistent, efficient, and sufficient statistics, is shown to have a cash value by means of the calculable measure of (ex ante) “risk-corrected certainty equivalents.” Needed qualifications and testings are also presented.     

On Tiku's robust procedure — a Bayesian insight

Tiku's robust procedure for testing mean and variance from nonnormal universe is examined from the Bayesian viewpoint. The posterior distribution of the scale parameter is derived and then approximated by a Laguerre polynomial expansion while the posterior distribution of the location parameter is approximated by a linear combination of t-distributions. For the example with Darwin's data, the approximations appear to be extremely good.     

Some Issues of Particular Concern to Sociologists As Academic Administrators

As a sociologist who has served in deanships and other university administrative positions in the past 15 years, the author has been particularly concerned with race/class/gender issues in academia. This paper identified some of the issues and discussed the relevance of sociological training in addressing them.     

Forgetting the founders*

The inability, or unwillingness, of 20^th‐century sociologists to move beyond the agenda bequeathed by Marx, Weber, and Durkheim is remarkable in view not only of the now outdated presuppositions shared by all three but of the increasing likelihood that the more important influence on the human behavioural sciences in the 21^st century will turn out to be Darwin's. Not only has the coming together of evolutionary theory, population genetics, and molecular biology shown that significantly more of human behaviour can be explained by the theory of natural selection than was previously recognized, but non‐reductionist explanations of cultural and social evolution from within a neo‐Darwinian paradigm can be framed in terms no longer vulnerable to the criticisms previously levelled against the application to sociology of Darwin's original insight about ‘descent with modification’.     

Estimating Contaminant Dose for Intermittent Dermal Contact: Model Development, Testing, and Application

Assessments of aggregate exposure to pesticides and other surface contamination in residential environments are often driven by assumptions about dermal contacts. Accurately predicting cumulative doses from realistic skin contact scenarios requires characterization of exposure scenarios, skin surface loading and unloading rates, and contaminant movement through the epidermis. In this article we (1) develop and test a finite-difference model of contaminant transport through the epidermis; (2) develop archetypal exposure scenarios based on behavioral data to estimate characteristic loading and unloading rates; and (3) quantify 24-hour accumulation below the epidermis by applying a Monte Carlo simulation of these archetypal exposure scenarios. The numerical model, called Transient Transport through the epiDERMis (TTDERM), allows us to account for variable exposure times and time between exposures, temporal and spatial variations in skin and compound properties, and uncertainty in model parameters. Using TTDERM we investigate the use of a macro-activity parameter (cumulative contact time) for predicting daily (24-hour) integrated uptake of pesticides during complex exposure scenarios. For characteristic child behaviors and hand loading and unloading rates, we find that a power law represents the relationship between cumulative contact time and cumulative mass transport through the skin. With almost no loss of reliability, this simple relationship can be used in place of the more complex micro-activity simulations that require activity data on one- to five-minute intervals. The methods developed in this study can be used to guide dermal exposure model refinements and exposure measurement study design.