Declining world fertility: trends,causes, implications

This Bulletin examines the evidence that the world's fertility has declined in recent years, the factors that appear to have accounted for the decline, and the implications for fertility and population growth rates to the end of the century. On the basis of a compilation of estimates available for all nations of the world, the authors derive estimates which indicate that the world's total fertility rate dropped from 4.6 to 4.1 births per woman between 1968 and 1975, thanks largely to an earlier and more rapid and universal decline in the fertility of less developed countries (LDCs) than had been anticipated. Statistical analysis of available data suggests that the socioeconomic progress made by LDCs in this period was not great enough to account for more than a proportion of the fertility decline and that organized family planning programs were a major contributing factor. The authors' projections, which are compared to similar projections from the World Bank, the United Nations, and the U.S. Bureau of the Census, indicate that, by the year 2000, less than 1/5 of the world's population will be in the "red danger" circle of explosive population growth (2.1% or more annually); most LDCs will be in a phase of fertility decline; and many of them -- along with most now developed countries -- will be at or near replacement level of fertility. The authors warn that "our optimistic prediction is premised upon a big IF -- if (organized) family planning (in LDCs) continues. It remains imperative that all of the developed nations of the world continue their contribution to this program undiminished."     

构建局队和谐关系才能促进统计事业发展

中央组建各级直属调查队是国务院加强统计工作的一项重大举措,其主要目的是增强国家统计的权威,提高统计的可信性,提高统计数据质量,提高统计工作抗干扰的能力。因为,在实际工作中,对统计的干扰是客观存在的。统计工作只对统计数据的真实性负责,而不能对项目的合法性和合理性负责。为了减少这种干扰,国务院决定把各地的三支国家调查队彻底独立升格,组建垂直国家管理的国家直属调查队,这是我国统计管理体制的重大改革,意义深远。随着时间推移,其作用和影响将会充分体现。一、正确认识局队的任务与职责国家统计局各级调查队既是国家统计局直属…     

Conjuncture and cultural reproduction in the process of embedding: social work practice in the context of government purchase of services in China

This paper focuses on the Chinese government’s policy of purchasing social services and discusses how relevant organisations provide social work and develop it within local socio-political and cultural contexts. An ethnographic research method was adopted for the study by the first author while participating in social work development in Q City. We argue that the policy of purchasing social services succeeded in achieving “embedded development” but also created a “conjuncture structure” in cultural reproduction. However, due toprofessional social workers in China have, in practice, passively responded to the conjuncture there has been a failure to reproduce professional values of social work in the Chinese cultural context. Therefore, further development of social work in China needs to strengthen cultural reflection in practical actions, focus on the exploration of cultural connections between social work practice and local communities, and enhance the cultural capacity of social workers in the local cultural context.     

四棱豆营养器官化感潜力的比较

以萝卜和菜心种子为受体,采用生物检测方法,对四棱豆根、茎和叶水浸液的化感潜力进行比较研究,结果表明：四棱豆根、茎和叶水浸液对萝卜和菜心种子萌发的抑制作用随水浸液处理浓度的增加呈增强趋势.根和茎水浸液对萝卜和菜心的根长均有抑制作用,且根的抑制效果高于茎,而叶表现为促进作用.水浸液对萝卜和菜心胚轴生长均有不同程度的促进作用.四棱豆叶水浸液对提高萝卜根冠比的效果明显,而茎和根水浸液对其影响较小.经四棱豆根、茎和叶水浸液处理后,均能明显降低菜心的根冠比,其中根水浸液的作用效果更为明显.     

Multidimensional poverty indices

This paper explores the axiomatic foundation of multidimensional poverty indices. Departing from the income approach which measures poverty by aggregating shortfalls of incomes from a pre-determined poverty-line income, a multidimensional index is a numerical representation of shortfalls of basic needs from some pre-specified minimum levels. The class of subgroup consistent poverty indices introduced by Foster and Shorrocks (1991) is generalized to the multidimensional context. New concepts necessary for the design of distribution-sensitive multidimensional poverty measures are introduced. Specific classes of subgroup consistent multidimensional poverty measures are derived based on sets of reasonable axioms. This paper also highlights the fact that domain restrictions may have a critical role in the design of multidimensional indices. Received: 1 March 1999/Accepted: 1 August 2000     

可数集类的共性集

讨论了有限集类在增补集合的情况下同阶共性集的相互联系，有限集类的共性集与可数集类的共性集之间的极限关系，得出了可数事件的共性事件概率公式．     

Efficient heterogeneous sampling for stochastic simulation with an illustration in health care applications

In modeling disease transmission, contacts are assumed to have different infection rates. A proper simulation must model the heterogeneity in the transmission rates. In this article, we present a computationally efficient algorithm that can be applied to a population with heterogeneous transmission rates. We conducted a simulation study to show that the algorithm is more efficient than other algorithms for sampling the disease transmission in a subset of the heterogeneous population. We use a valid stochastic model of pandemic influenza to illustrate the algorithm and to estimate the overall infection attack rates of influenza A (H1N1) in a Canadian city.     

变差可积鞅及条件变差可积鞅的最优系数不等式

设f是条件变差可积鞅 ,则有‖f‖p≤ 1P‖f‖ap　 0 相似文献   

Determinants of contraceptive switching behavior in rural Sri Lanka

This study examines the influence of a selected set of determinants of contraceptive method switching in rural Sri Lanka. Of interest is the question of how change in contraceptive practice at the individual level can account for patterns observed at the aggregate level. Based on calendar data on contraceptive use over a 3-year period, collected for more than 3,000 married women in a 1986 survey, the multivariate analysis shows that women who attain all or a significant proportion of their desired fertility tend to switch to more effective methods. Women who experience method failure tend to switch methods, usually to a type that is more effective. The woman's background determinants of age and education have small but significant effects on method switching, whereas the effect of household economic well-being is not significant. There is strong indication that rural couples are practicing contraception in a nonrandom fashion, switching methods in accordance with changes in their fertility motivations and contraceptive experience.