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971.
This paper pools cross-section data to obtain an estimate of the overall effects of unions on relative wages for the period 1967 through 1977. We found the average union wage premium for all workers to be roughly 24 percent, but that this premium varies substantially between subgroups of workers. Our analysis showed that real wage rates increased faster in the union sector than in the nonunion sector between 1967 through 1977. However, we found that this relative growth pattern in wages was caused by economic conditions rather than in any fundamental shift in the power of unions. We wish to thank James S. Cunningham, H. Gregg Lewis, and John Pencavel for helpful comments.  相似文献   
972.
When subjects are not found at home in a social survey, the question arises whether the subsample encountered at home, on the first or subsequent visits, is random or biased. A procedure is presented by which this question can be statistically tested, by comparing the decline rate in unfound subjects, over repeated visits, with those expected if the subsample were random or strongly biased. The randomness of the subsamples can be compared between the first and subsequent visits. The procedure can be carried out during a programme of revisits, to check quickly whether a satisfactory sample is being obtained.  相似文献   
973.
Applications of methods for carcinogenic risk assessment often focus on estimating lifetime cancer risk. With intermittent or time-dependent exposures, lifetime risk is often approximated on the basis of a lifetime average daily dose (LADD). In this article, we show that there exists a lifetime equivalent constant dose (LECD) which leads to the same lifetime risk as the actual time-dependent exposure pattern. The ratio C = LECD/LADD then provides a measure of accuracy of risk estimates based on the LADD, as well as a basis for correcting such estimates. Theoretical results derived under the classical multistage model and the two-stage birth-death-mutation model suggest that the maximum value of C, which represents the factor by which the LADD may lead to underestimates of risk, will often lie in the range of 2- to 5-fold. The practical application of these results is illustrated in the case of astronauts subjected to relatively short-term exposure to volatile organics in a closed space station environment, and in the case of the ingestion of pesticide residues in food where consumption patterns vary with age.  相似文献   
974.
This paper extends the existing literature concerning the relationship between two parameter decision models and those based on expected utility in two main directions. The first relaxes Meyer's location and scale (or Sinn's linear class) condition and shows that a two-parameter representation of preferences over uncertain prospects and the expected utility representation yield consistent rankings of random variables when the decision maker's choice set is restricted to random variables differing by mean shifts and monotone meanpreserving spreads. The second shows that the rank-dependent expected utility model is also consistent with two-parameter ranking methods if the probability transform satisfies certain dominance conditions. The main implication of these results is that the simple two-parameter model can be used to analyze the comparative statics properties of a wide variety of economic models, including those with multiple sources of uncertainty when the random variables are comonotonic. To illustrate this point, we apply our results to the problem of optimal portfolio investment with random initial wealth. We find that it is relatively easy to obtain strong global comparative statics results even if preferences do not satisfy the independence axiom.  相似文献   
975.
Current approaches to the assessment of job attitudes—for use in job redesign—seem to centre upon the importance of job characteristics, such as those within the Job Characteristics Model. Data collection is largely through well-founded, repeatable, formal questionnaires. It is argued that a broader, ergonomics perspective is required, stressing the importance of job holders' attitudes to the technology being used, the physical environment and workplace, and procedures in support of work, such as training. Furthermore, if we wish to promote the participation of those whose work is being redesigned, the traditional and scientifically respectable questionnaire may not be the correct instrument. Data gathered by means of informal semi-structured discussion may better reflect the concerns and priorities of the people doing the work. Perhaps, to paraphrase Marshall McLuhan, formal job attitude instruments used alone are 'hot media', in the sense of being well-filled with data but low in participation. Informal discussion methods could be seen then as a 'cool medium', high in participation or completion by the audience (McLuhan 1964, pp. 22-23).  相似文献   
976.
An approach, using biomarkers (biological responses) for assessing the biological and ecological significance of contaminants present in the environment is described. Living organisms integrate exposure to contaminants in their environment and respond in some measurable and predictable way. Responses are observed at several levels of biological organization from the biomolecular level, where pollutants can cause damage to critical cellular macromolecules and elicit defensive strategies such as detoxication and repair mechanisms, to the organismal level, where severe disturbances are manifested as impairment in growth, reproduction, developmental abnormalities, or decreased survival. Biomarkers can provide not only evidence of exposure to a broad spectrum of anthropogenic chemicals, but also a temporally integrated measure of bioavailable contaminant levels. A suite of biomarkers are evaluated over time to determine the magnitude of the problem and possible consequences. Relationships between biomarker response and adverse ecological effects are determined from estimates of animal health and population structure.  相似文献   
977.
978.
Global strategic marketing planning has emerged as a key process in managing today's worldwide marketplace. This survey of 90 large American global corporations reveals that most are bottom-up planners. US firms appear to have distinct cost and numbers orientations. Industry and competitive analyses are used in many companies, although managers appear to lack suitable frameworks for SWOT analyses. Economic climate changes tend to be most disruptive to global planning efforts. When faced with non-achievement of goals, most firms reformulate both objectives and strategies.  相似文献   
979.
Conventional wisdom suggests that union members and their families are more politically active, and more likely to vote, than nonmembers. This study presents, to our knowledge, the first systematic empirical examination of that conventional wisdom. Results suggest that union members are more likely than nonmembers to vote in a general election, and that union campaign efforts increase voter turnout generally. There is no evidence, however, that union family members are more likely to vote than nonmembers, or that union status affects an individual’s likelihood of voting in a primary election. The authors wish to thank Robert Perloff, Donna Sockell, and an anonymous referee for helpful comments on an earlier draft of this paper. This study was partially supported by a Columbia University Graduate School of Business Faculty Research Fellowship and a Faculty Research Grant from the University of Pittsburgh Graduate School of Business.  相似文献   
980.
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