限价指令簿的价格发现功能

基于上海证券交易所Level—2行情数据,本文运用Hasbrouck信息份额方法分别估计最近成交价、限价指令簿中最优买卖报价及第2—10档次买卖报价在价格发现中的贡献度,以考察限价指令簿的价格发现功能,尤其关注次优限价指令对价格发现的影响。我们认为,次优限价指令有助于价格发现,其贡献度为21.43%,而且其贡献度随指令主动性的下降而递减;最优限价指令的贡献度最大,为63.82%;最近成交价的贡献度最小,为14.76%;另外,本文还考察了个股横截面特征是否影响次优限价指令对价格发现的贡献度。实证结果表明:随着个股交易活跃度的下降,投资者更倾向于提交限价指令,从而导致次优限价指令对价格发现的贡献度增加;同时,其贡献度随公司规模和Beta系数的上升而单调下降。     

社会保障对家庭人力资本数量的影响机理

国外越来越多的经济学家着力研究社会保障制度的经济效应.随着中国社会保障制度的建立和完善,有必要分析这项制度对微观主体经济行为的影响机理.建立一个两时期的交叠世代模式,分别对自由放任或基金制经济和现收现付制经济中家庭的生育决策和人力资本投资决策进行了分析.发现现收现付制经济中家庭倾向于减少对子女的投入,从而产生了一种内在的、自动的降低生育率的机制.因此,建议在农村建立现收现付的养老保险制度,改变农村的养老模式,同时加大对农村劳动力的就业促进和就业培训,促使农村人口由数量向质量的转变.     

基于关联分析的兵团出口贸易发展水平研究

该文利用兵团近10年出口贸易数据,构建出口贸易发展水平评价体系并进行了关联分析,结果表明:兵团出口贸易结构不断改善,出口贸易规模以相对平稳的速度不断扩张,出口贸易竞争力不断提升,但出口贸易效益却在不断下降。各指标对出口贸易发展水平的影响依次是出口贸易结构、出口贸易规模、出口贸易竞争力、出口贸易效益和出口贸易速度。总体上,兵团出口贸易发展水平在波动中不断提升。     

中国的生育水平——基于模拟的验证

中国的实际生育水平一直存在争议,2010年的普查数据为我们提供了考察生育水平的新证据。本文根据2000年人口普查资料,使用人口模拟模型,选取不同的生育水平方案,来模拟2001—2010年历年的出生人口数量和2010年的人口总量,以判断2000—2010年生育水平。结果表明,现行的总和生育率在1.7以下,1.6左右,2010年在1.6以下,但降到1.5以下的可能性也非常大。为了避免低生育的更进一步的严重后果,中国应该适时地完善生育政策。     

服务水平约束下的建筑安装行业多仓库联合库存系统模型研究

本文针对建筑安装行业库存管理的特点,对其不同地点的多个仓库的库存方式进行综合分析,建立了服务水平约束下的建筑安装行业多仓库联合库存系统模型,给出了相应的数学模型与算法。通过算例验证表明,服务水平约束下的建筑安装行业多仓库联合库存系统模型可以有效降低建设项目的库存成本,对增加企业利润有着十分重要的现实意义。     

Data quality and accuracy of United Nations population projections, 1950-95

Between 1951 and 1998, the United Nations (UN) published 16 sets of population projections for the world, its major regions, and countries. This paper reports the accuracy of the projection results. I analyse the quality of the historical data used for the base populations of the projections, and for extrapolating fertility and mortality. I study also the impact this quality has had on the accuracy of the projection results. Results and assumptions for the sets of projections are compared with corresponding estimates from the UN 1998 Revision for total fertility and life expectancy at birth, total population, and the projected age structures. The report covers seven major regions (Africa, Asia, the former USSR, Europe, Northern America, Latin America, and Oceania) and the largest ten countries of the world as of 1998 (China, India, the USA, Indonesia, Brazil, Pakistan, Russia, Japan, Bangladesh, and Nigeria).     

The quality–quantity trade-off in fertility across parent earnings levels: a test for credit market failure

The dominant economic theory of the family explains the negative correlation between family size and child achievement, a ‘quality–quantity trade-off’, through borrowing constraints and credit market failure. This paper presents a model in which the opportunity cost of time spent with children is increasing, thus creating a trade-off even in economies with perfect credit markets. While both produce a family size effect, temporal and financial constraints predict different patterns for the trade-off across levels of parent income. Using data from the National Child Development Study, the trade-off is found even among high-earning families who presumably do not face credit constraints. Moreover, the trade-off does not grow as parent earnings diminish. Both of these findings suggest that temporal and not financial constraints explain the quality–quantity trade-off.

Marriage form and fertility in rural China: an investigation in three counties

Using data from two surveys in three counties where the prevalence of uxorilocal marriage differs greatly, this paper analyzes impact of marriage form, individual, family, and social factors on fertility and its regional differences. The results show that, under the Chinese patrilineal joint family system, uxorilocal marriage does not universally increase fertility, which is likely to be determined by other factors. It is further found that fertility differs greatly in the three regions, and is significantly lower in regions where uxorilocal marriage is common than in regions where virilocal marriage is dominant. Women’s marriage cohort, age at first marriage, and number of sisters all have significant effects on fertility. These findings address the process and consequences of change in rural family and marriage customs during the current demographic and social transition.     

中国人口迁移与生育率关系研究

本文利用2000年人口普查数据,考察了中国人口迁移与生育率的关系。通过比较农村本地人口、城市本地人口和流动迁移人口三个人口群体在生育率上的差异,并进行多元统计分析,结果表明,流动迁移对生育率有着非常显著影响,城市外来人口的生育率不仅显著低于农村本地人口,而且也低于城市本地人口;远期流迁人口的生育率要低于近期流迁人口的生育率。中国人口迁移与生育率的关系出现了与已有的迁移生育率理论的不一致。1990年代中国的迁移生育率发生了转变。     

少子老龄化时代人口学教育的若干思考

少子化、老龄化和人口减少问题将对人类社会的持续发展产生深远的影响,如何引导人们以长期和超长期的视野来考量少子化问题,形成适应新时代的新人口观,正是少子老龄化、人口减少时代人口学教育的责任和意义所在。而更替水平这一基本概念和人口增减机理有助于学生对人口减少等问题的正确理解。