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A company bidding by sealed tender needs to know the relationship between their bid price and their chances of winning the contract. Previously published models for computing the probability of winning are examined and found to be inaccurate. The problem is reformulated, and a new general predictive model for computing the probability of winning is developed. The method of computation is illustrated by a simple worked example. 相似文献
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Prior work finds declining immigrant quality in the postwar period that is linked to source-country and skill-composition changes associated with the 1965 Immigration Act. This paper uses a unique panel of foreign- and native-born American Economic Association members to show that the highly skilled experienced a similar shift away from European migrants toward those from Asia. However, the findings do not indicate that this change in source-country composition has been accompanied by a decline in quality; rather, the most recent cohorts of foreign-born economists appear to be more productive than their native counterparts. 相似文献
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This report investigates trends in the initial phases of the family-building process for Swedish women in five-year cohorts born between 1936 and 1960, using life-table techniques. Non-marital cohabitation was much more widespread in our pre-World War II cohort than has been realized previously. Among never-married women, first-birth fertility was remarkably stable for those in and those not in a consensual union alike. Strong increases in non-marital fertility have resulted from progressively increasing exposure to the higher fertility of consensual unions instead of to the very low fertility of single women. Cohabitational first-birth fertility is not high compared with marital fertility. 相似文献
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Jan M. Hoem 《Revue europeenne de demographie》1986,2(2):113-133
The impact of education on formation of first unions is analyzed using interview data from a sample of Swedish women born in 1936–1960. A distinction is made between achieved level of education and the effect of being a student. The former appears to have little effect, but students start consensual unions at lower rates than corresponding non-students, and they also marry at much lower rates. Social background has not been important for marriage formation, but it has been for cohabitation, which was pioneered by the working class. There is no evidence that modern cohabitation started as a campus movement. 相似文献
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This paper throws some light on changing family-building patterns in Sweden during the 1960s and 1970s. The family-building events analyzed are first informal cohabitation, first marriage, birth of first child (both outside a union and within a consensual union), and separations from childless informal cohabitation. Results from three previous studies are first summarized. These analyze the patterns by socio-economic and regional origin, applying multiple-decrement techniques separately for each background factor. The new results presented here are based on analyses that use multiplicative hazard models, permitting isolation of the effects of socio-economic background and region of childhood and adolescence respectively. It is generally found that socio-economic background is more important than the region where the woman grew up. Marriage intensities, however, which exhibit a clear regional pattern, are exceptions to this. 相似文献
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Italy has long been regarded as the country with negligible non-marital cohabitation par excellence, but lately the pattern
has begun to change and entry into consensual unions has increased strongly in younger Italian generations. This article is
devoted to a study of such features between 1980 and 2003 based on the data from the Italian variant of the Gender and Generations
Survey, Round 1. We consider entry into marriage and entry into cohabitation as competing risks and show how the incidence
of cohabitation consistently much lower but has increased by some 70% over the 20-odd years of our study, while the marriage
rate has dropped by almost as much. We find great variation across major regions of the country. The rise in cohabitation
is confined to Northern and Central Italy, while the risk of marriage formation has declined strongly all over the country.
Unlike previous investigations, our data suggest that non-marital cohabitation may be taking over whatever minor role civil
marriage has had in Italian union formation. 相似文献
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NS Pine RA Tarrant AC Lyons JM Leathem 《Kōtuitui : New Zealand Journal of Social Sciences Online》2015,10(2):116-125
Natural disasters are harmful worldwide events that inflict multiple psychosocial impacts on disaster-exposed individuals. A significant proportion of affected individuals are teenagers (13–18 years old) who, compared with adults, have been historically overlooked in disaster research. The literature is particularly sparse concerning teenagers’ recovery from natural disasters, specifically what recovery means to them and the contributing factors towards their positive recovery. Therefore, the aim of the current study was to gain deeper insight into this largely unexplored area by conducting five focus groups with teenagers (16–18 years) who experienced at least one of the Canterbury, New Zealand, earthquakes since and including the initial September 2010 earthquake. This study directly asked teenagers about their recovery over the three years after the initial earthquakes, with data being analysed using thematic analysis. Two main themes were identified: (1) perceptions of recovery, with three sub-themes (i) knowledge and being less frightened, (ii) talking about the earthquakes and (iii) shift in perspectives; and (2) contributing factors to recovery, with three sub-themes (i) participation in the community response, (ii) returning to school and (iii) the rebuild of Christchurch. These factors provide insight into how we can better support the recovery process for disaster-exposed teenagers to reduce long-term distress. 相似文献
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We examine the financial linkage between the London and Amsterdam financial markets using stock prices recorded in each market over the period 1723-94 in conjunction with tests for common trends, cycles, and regime shifts. These tests reveal a surprising degree of integration between the markets as their prices move together in both the short and long run. Moreover, shocks to the assets translate quickly and accurately between markets. It also appears that Dutch investment did not destabilize London markets and stock prices in London were the primary determinant of prices in Amsterdam. 相似文献
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Using data for 555,038 pregnancies conceived in the Czech Republic in 1987-1990, we show that pronounced differences in fetal survival in the middle trimester of pregnancy by marital status, educational level, and labor force attachment become much smaller at full term; survival differences by age at conception and number of previous deliveries show relatively constant proportional hazards throughout gestation. Social inequalities in postpartum life chances have been documented previously, but we show that similar inequalities exist before birth. 相似文献