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31.
This paper examines differences in earnings by occupations, and within occupations by sex and by race, on the basis of the 1/100 Public Use Samples of the 1960 and 1970 U.S. Population Censuses. It employs interval analysis to establish 32 categories of occupations with similar characteristics. Little relation was found between mean earnings of occupational groups and the degree of earnings inequality within them. When the figures are examined by sex, it was found that men, on average, earned over twice as much as women in both years, but women's earnings were more unequally distributed (as measured by the Gini coefficient). Women are concentrated in the traditional “female” occupations, which tend to be those at the bottom of the earnings scale, and men have a monopoly of the higher paid occupations. But mean earnings for men exceeded those for women in all occupational groups except one, even in the primarily female occupations. Standardizing first for occupational distribution and then for earnings by occupation, it was found that earnings differences between males and females within occupation had a greater impact on the overall male-female earnings ratio than did differences in occupational distribution by sex. In contrast, when the figures are examined by race, the change in occupational distribution (primarily the movement of blacks out of farming and of blacks and Spanish speakers out of personal services) was the major factor. There was also a considerable degree of earnings inequality within demographic groups. The degree of inequality was in the main reduced when the demographic groups were subdivided into occupations, but it was still substantial. Additional factors like time worked, schooling, and experience must be taken into consideration in understanding this phenomenon.  相似文献   
32.
In questo lavoro viene fornita una nuova caratterizzazione dell'ammissibilità attraverso un adeguato uso della nozione di ammissibilità parziale. Questa caratterizzazione consente di affrontare le questioni riguardanti la completezza della classe delle decisioni ammissibiliti sotto condizioni «maneggevoli». Fornisce inoltre un approccio unificante al problema della completezza che consente di derivare, come casi particolari, alcuni risultati già noti nella letteratura sull'argomento.
In this paper a new characterization of admissibility is given for general decision problems. It is based on an adequate use of the notion of partial admissibility.A general decision problem is usually synthetized by a triplet (, , ) where is the states (or parameters) space, the set of available decisions and is a family of real valued functions defined on and expressing numerically the consequences of choosing when the state is . The set is regarded as a subset of the space of all real valued functions on endowed with the topology of pointwise convergence.As for as admissibility is concerned all the pertinent information about decisions are contained in the corresponding functionsW .This allows to introduce a notion of partial admissibility through the neigh-bourhoods of this topology. Admissibile decisions are then shown to be limits of monotone non increasing sequences of partially admissible decisions.Moreover this topological characterization allows to prove the completeness of classes of admissible decisions under acceptable systems of conditions which contain as special cases, known results in literature.


Lavoro svolto nell'ambito del Gruppo Nazionale per l'Analisi Funzionale e le sue Applicazioni del C.N.R.  相似文献   
33.
A bstract . In the eyes of European scholars, publicists and politicians who studied Henry George's work, he, as a social philosopher , had adopted the position of the natural law philosophers of the 18th century. The latter inspired the Declaration of Independence, the U.S. Constitution and its Bill of Rights, as well as the poiitical philosophy of Jeffersonian democracy , the ethos of the 18th and 19th century pioneer settlers. George rejected Social Darwinism. He saw natural law as the only true and reliable basis for a just social order. Like Karl Marx he mastered Ricardian economics ; unlike Marx, George made two factors the basis of his system, labor and land. George saw that each person had a natural right —and a natural imperative for survival —to apply his or her productive capacity to the earth –as living space and as storehouse of nutrients and raw materials. The person-land relationship , he discovered, lay at the basis of human culture. And so the land's rent , now monopolized by the few, had to be appropriated to meet the needs of society, most efficiently and justly by a land value tax.  相似文献   
34.
This paper considers why firms differ in the degree to which they rely on their internal R&D organization for generating new technologies (induced innovations) rather than on existing external technology markets (purchased innovations). An empirical model is suggested to explan inter-firm differences in the percentage of new technology induced through R&D efforts. The analysis suggests that such differences are systematically related to the firm's size, its competative environment, and its degree of diversification.  相似文献   
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Here we propose a few estimators of θ, in addition to those studied in Goria (1978), the point of discontinuity of the probability density $$f(x,\theta ) = \frac{1}{{2\Gamma (\alpha )}}e^{ - |x - \theta |} |x - \theta |^{\alpha - 1} ,$$ for $$0< \alpha< 1, - \infty< x< \infty , - \infty< \theta< \infty .$$ We establish the consistency and the optimality of the Bayes and the maximum probability estimators. Despite their nice properties, these estimators are not easy to compute in this case and their effective computation depends on the knowledge of the exponent α. Hence, we propose another class of estimators, dependent upon the spacings of the observations, computable without actual knowledge of the value of α as long as it is known that α < α0 < 1: we show that these estimators converge at the best possible rate. We further demonstrate, using a modified version of the maximum probability estimator's technique, that the tails of the density do not substantially effect their efficiency. Finally a bivariate family of densities, having a ridge dependent on the parameter θ, is considered and it is shown that this family exhibits features similar to the univariate case, and thus, the necessary modifications of the arguments of the univariate case are utilized for the estimation of θ in this bivariate example.  相似文献   
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In the project Technology in Secondary Education: Problem-solving in Teaching/learning Packages, two experiments regarding a construction problem and an explanation problem were conducted, in which two variants of a teching/learning package (strongly structuredvs. weakly structured) were compared. Only with the strongly structured instructional variant of the package for the explanation problem did the pupils come to a quick solution of the problem. In both experiments, the factors that influenced the problem-solving processes of the pupils were investigated. The results are of importance for curriculum developers and the authors of teaching/learning packages for Technology but further research into the factors influencing the problem solving process of pupils is necessary.  相似文献   
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