人口死亡研究的展开

当前 ,在人口死亡现象和研究方面有一些新的内容值得注意 :(1 )人口寿命的延长趋势。发达国家的人口寿命增加的幅度虽然很小 ,但还有所增加 ,人口寿命增长是否有极限 ?发展中国家的平均寿命一度增加很快 ,但现在已放慢了速度。今后世界人口的寿命将如何变化 ?(2 )从人口死亡到人口健康的研究。随着人的平均寿命的延长和人口老龄化 ,不健康的人群绝对数和占全部人口的相对比例也增大。人们对生命质量的关心 ,呼唤着对人口健康研究的重视。 (3 )环境对人口健康 ,人口死亡的影响 ,人口、资源、环境问题已成为全球共同关注的问题。由于人们不合理的生产和生活方式导致了自然环境的破坏 ,已危及到人类的自身的生存。环境公害 ,有毒物质对人体的伤害 ,几乎无人能够幸免。 (4 )“安乐死”的问题。在人类历史上 ,自然死亡一直被人们认为是结束生命的唯一合理形式。这个理念现在受到了挑战。关于安乐死是否合理牵涉到现存的人性、伦理、道德和法律等诸多方面 ,要判断是非 ,可说是世界上的一道难题。     

中国高龄死亡模式及其与瑞典、日本的比较分析

本文发现只有二个参数的莰尼斯托 (Kannisto)模型 (即简化的罗吉斯特模型 )对中国高龄老人死亡率的拟合效果好于其他五个模型。中国与瑞典、日本 96岁以上的年龄别死亡率比较相近 ,而中国 96岁以下的年龄别死亡率显著高于瑞典、日本。我们认为这一有趣的趋同现象可能主要是由中国高龄老人“劣淘优存”的选择性更强而形成的。我们还发现与发达国家模式类似 ,中国的死亡率随着年龄增加而升高的趋势在 96岁以后的特高年龄段减缓。     

Ten Thousand Tonga: A Longitudinal Anthropological Study from Southern Zambia, 1956–1991

The Gwembe Study was launched in 1956 to monitor the responses of 57,000 Tonga-speakers from the Middle Zambezi Valley to involuntary relocation. Since then, periodic censuses and frequent field visits have generated a wide variety of information. This article examines the demography of four Gwembe Tonga villages from 1956 to 1991, a period characterized first by relocation, then prosperity, and finally by economic hardship. White nuptiality does not respond significantly to socio-economic trends, marital fertility falls sharply during relocation, rebounds with the onset of prosperity, and decreases slowly during the most recent decade of economic hardship. Mortality of the very young and old is also sensitive to such changes. There is striking excess male mortality in all periods, especially among male infants and in particular male twins. The sex ratio at ‘birth’ is 92. This abnormal sex ratio at birth may be the result of conscious sex preference favouring females.     

Drought,Migration and Population Growth in the Sahel: The Case of the Malian Gourma: 1900–1991

This paper explores the development of the population of the Gourma in Northern Mali from the beginning of this century to the present. As part of Northern Sahel, the area has been hard-hit by at least four droughts this century and is among the least developed in Mali. The data used include the available population censuses, colonial records and recent survey research. The droughts of 1973 and 1984 may have increased child mortality, but the most important effects may have been short-term reductions in fertility, as well as increased migration. While approximately 30 per cent of adult men are absent, the overall picture of migration is much more complex than simply one of emigration, as migration into the Gourma and internal redistribution of population also play an important role.     

Population pressure and fertility in pre-transition Thailand

Before the demographic transition in Thailand, fertility was high, but not uniformly so. As in other pre-transition settings, Thai fertility responded to pressures and opportunities created by socioeconomic structure and land availability. Drawing upon provincial data from the 1947 and 1960 censuses of Thailand, we find a strong 'frontier effect' on Thai fertility in the 1950s. Fertility was higher in sparsely settled frontier provinces and lower in provinces with higher population density relative to cultivatable land. This finding is robust and holds up with controls for agricultural employment, land quality, and the sex ratio (an indicator of sex-selective migration). The effect of population pressure lowers the likelihood of marriage and of marital fertility. The findings from Thailand are consistent with the research of Easterlin on the nineteenth century United States and with other pre-transition societies. We suggest how demographic transition theory might be broadened to include fertility dynamics in pre-transition societies.     

The Economic Theory of Fertility Over Three Decades

A large proportion of cohabitors in the Statistics Norway Omnibus Surveys of 1996 reported economic reasons for their hesitation to marry, and in particular the costs of the wedding. In line with this, the Norwegian Family and Occupation Survey of 1988 revealed effects both of women's cumulated income and men's non-employment on the actual choice of union type. Also some other evidence suggests that affordability matters, although there are plausible alternative interpretations. On the other hand, several estimates suggest that economic strength does not induce marriage. Since there also has been no deterioration of young adults' economic situation in Norway, except for the delay of economic independence owing to longer college enrolment, one can hardly claim that lack of affordability is a dominating force behind the massive drift away from marriage. The analysis is anchored in a theoretical framework that may prove useful in other studies of cohabitation as an alternative to marriage.     

New insights into the Far Eastern pattern of mortality

This paper investigates the consequences of using different economic status proxies on the estimated impact of economic status and other determinants of fertility. Using micro survey data from Ghana and Peru, we find that the proxies for income that best predict fertility are a principal components score of the ownership of consumer durable goods and a simple sum of ownership of these durable goods. Furthermore, the choice of the proxy generally has a minor influence on the predicted effects of the control variables. We compare the results from using a restricted set of proxies, such as those available in the Demographic and Health Surveys, with the results obtained using a lengthier set of proxies. Our results suggest implications beyond fertility analyses by providing researchers with an awareness of the sensitivity of microanalyses to the treatment of economic status. Our results also suggest practical recommendations for the collection of survey data.     

Comparison of Four Methods for Estimating Complete Life Tables from Abridged Life Tables Using Mortality Data Supplied to EUROCARE-3

ABSTRACT

To estimate mortality due to cancer, it is necessary to have mortality data by year of age in the population of cancer patients. When such data are not available, estimating one-year (complete) life tables from five-year (abridged) life tables is necessary. Four such methods—Elandt–Johnson, Kostaki, Brass logit, and Akima spline methods—are compared with respect to 782 empirical complete life tables pertaining to 19 European regions or countries, from 1954 to 2000. Abridged life tables are first derived from the empirical ones, then used to produce one-year-life tables by each of the four methods. These reconstituted complete life tables are then compared with the empirical complete life tables. Among the four methods, the Elandt–Johnson demographic method produces the best reconstitutions at adult ages, specifically those ages at which observed cancer survival needs to be corrected.     

Understanding Mortality Rate Deceleration and Heterogeneity

ABSTRACT

Generic relationships between heterogeneity in population frailty and flattening of aggregate population hazard functions at extreme ages are drawn from classical mathematical results on the limiting behavior of Laplace transforms. In particular, it shows that the population hazard function converges to a constant precisely when the distribution of unobserved heterogeneity in initial mortalities behaves asymptotically as a polynomial near zero.     

The Optimal Trade-Off Between Quality and Quantity with Unknown Number of Survivors

In a model of endogenous fertility where individuals know the probability of child survival but not the final number of survivors, parents do not always formulate a precautionary demand for children. For some utility functions, parents have fewer children than what they would have in a situation in which the number of survivors is known earlier. The properties of the optimal economic policy depend on the degree to which the social welfare function takes ignorance into account. If social welfare is evaluated after parents know how many children survived, the parental response to uncertainty is socially inefficient. Individual decisions then should be corrected through tax or transfer on both births and education. This property helps determine the optimal public response to mortality crisis in the presence of educational externalities.