Science and Decisions: Advancing Risk Assessment

At the request of the U.S. Environmental Protection Agency (EPA), the National Research Council (NRC) recently completed a major report, Science and Decisions: Advancing Risk Assessment, that is intended to strengthen the scientific basis, credibility, and effectiveness of risk assessment practices and subsequent risk management decisions. The report describes the challenges faced by risk assessment and the need to consider improvements in both the technical analyses of risk assessments (i.e., the development and use of scientific information to improve risk characterization) and the utility of risk assessments (i.e., making assessments more relevant and useful for risk management decisions). The report tackles a number of topics relating to improvements in the process, including the design and framing of risk assessments, uncertainty and variability characterization, selection and use of defaults, unification of cancer and noncancer dose‐response assessment, cumulative risk assessment, and the need to increase EPA's capacity to address these improvements. This article describes and summarizes the NRC report, with an eye toward its implications for risk assessment practices at EPA.     

Weiner's attribution theory and female orgasmic consistency

In a study of female orgasmic functioning, hypotheses derived from Weiner's (1974) achievement‐motivation model of attribution theory were contrasted with those from a model of self‐serving attributional bias. A 40‐item Sexual Behavior Questionnaire that elicited expectations and causal attributions for orgasmic and nonorgasmic coital outcomes was administered to 87 women. Predictions that (a) unexpected orgasmic outcomes will be attributed to unstable causes, (b) expectancy for future outcomes will depend on the stability of attributions made for previous outcomes, and (c) attributions for coital outcomes will be consistent with previous personal history were confirmed for high, but not low orgasmic consistency women (all ps < .05). High consistency women used a typically masculine strategy, attributing success to stable, internal causes and failure to unstable, external causes. Low consistency women, on the other hand, did not make attributions consistent with their previous history. They employed a self‐handicapping strategy by blaming themselves for failure and not taking credit for success. These results, consistent with previous attributional literature, suggest that modifications need to be made in Weiner's model as it is extended to this clinical area.     

Avoidance of Heights on the Visual Cliff in Newly Walking Infants

Work with infants on the “visual cliff” links avoidance of drop‐offs to experience with self‐produced locomotion. Adolph's (2002) research on infants' perception of slope and gap traversability suggests that learning to avoid falling down is highly specific to the postural context in which it occurs. Infants, for example, who have learned to avoid crossing risky slopes while crawling must learn anew such avoidance when they start walking. Do newly walking infants avoid crossing the drop‐off of the visual cliff? Twenty prewalking but experienced crawling infants were compared with 20 similarly aged newly walking infants on their reactions to the visual cliff. Newly walking infants avoided moving onto the cliff's deep side even more consistently than did the prewalking crawlers. Thus, in the context of drop‐offs in visual texture, our results show that once avoidance of drop‐offs is established under conditions of crawling, it is developmentally maintained once infants begin walking.     

The attitudes of American sociologists toward causal theories of male homosexuality

The origin of homosexuality has been the subject of systematic study in many disciplines during the previous century. In the social science literature, two general models concerning the etiology of homosexuality have emerged, the essentialist model and the constructionist model. This article reviews these two models and provides empirical data on their relative support. Support for each model has been gauged by assessing the opinions of sociologists. Data was obtained from a random sample of sociologists teaching in colleges and universities throughout the United States. The major finding is that the majority of sociologists now endorse the essentialist position.     

Housing Well-Being: Developing and Validating a Measure

Housing well-being refers to the home resident’s cumulative positive and negative affect associated with the purchase, preparation, ownership, use, and maintenance of the current home, and the selling of the previous home. Housing well-being is assumed to occur when the home is bought with the least amount of effort (purchase), the home is prepared for use to meet the needs of the new occupants (preparation), ownership signals status and enhances the home owner’s financial portfolio (ownership), the home serves the housing needs of the residents (use), the maintenance, renovation, and repair in the home are minimal, least costly, and effortless (maintenance), and the sale of the home is transacted with the least amount of effort and most financial gain (selling). Based on this conceptualization of housing well-being, we conducted an exploratory study to identify the sources of satisfaction related to the purchase, preparation, ownership, use, and maintenance of the current home, and the selling of the previous home. The exploratory study also helped us articulate a theoretical model describing the interrelationships among the housing well-being constructs and their consequence: the perceived quality-of-life (QOL) impact of the home. The exploratory study helped us also to develop survey measures, which in turn were validated through two additional studies involving surveys of home owners in the US and Korea.     

垄断竞争和最优的产品多样化

比较分析在垄断力量存在时市场均衡及最优资源分配的各种情形就会发现,垄断力量和市场扭曲的方向并没有显著的关系,在弹性不变的效用函数情形下,市场解能达到有约束的帕累托最优,而与弹性数值无关。对于可变弹性,市场解对最优的偏离是不确定的。具有非对称的需求和非对称的成本的条件下,市场偏离无弹性和高成本的商品。