中国人口老龄化变化趋势及完善养老保险体制的研究

本文利用全国人口普查和经常性统计的有关资料，在不同的人口政策目标参数假设下，根据中国人口预测系统（CPPS）和人口生命表对今后45年中国人口老龄化的变化趋势进行了分析和预测。根据预测结果，通过较全面系统地分析中国社会养老保险体制的现状，指出了其存在的问题，特别是在中国人口老龄化快速发展趋势冲击下已经出现及可能出现的问题。在此基础上，提出了几点具有可操作性的改革和完善养老保险体制、退休及人口生育等方面的政策建议。     

Simpler Probabilistic Population Forecasts: Making Scenarios Work

The traditional high-low-medium scenario approach to quantifying uncertainty in population forecasts has been criticized as lacking probabilistic meaning and consistency. This paper shows, under certain assumptions, how appropriately calibrated scenarios can be used to approximate the uncertainty intervals on future population size and age structure obtained with fully stochastic forecasts. As many forecasting organizations already produce scenarios and because dealing with them is familiar territory, the methods presented here offer an attractive intermediate position between probabilistically inconsistent scenario analysis and fully stochastic forecasts.     

Regional, national, and spatially explicit scenarios of demographic and economic change based on SRES

We report here spatially explicit scenario interpretations for population and economic activity (GDP) for the time period 1990 to 2100 based on three scenarios (A2, B1, and B2) from the IPCC Special Report on Emissions Scenarios (SRES). At the highest degree of spatial detail, the scenario indicators are calculated at a 0.5 by 0.5 degree resolution. All three scenarios follow the qualitative scenario characteristics, as outlined in the original SRES scenarios. Two scenarios (B1 and B2) also follow (with minor adjustments due to scenario improvements) the original SRES quantifications at the level of 4 and 11 world regions respectively. The quantification of the original SRES A2 scenario has been revised to reflect recent changing perceptions on the demographic outlook of world population growth. In this revised “high population growth” scenario, A2r world population reaches some 12 billion by 2100 (as opposed to some 15 billion in the original SRES A2 scenario) and is characterized by a “delayed fertility transition” that is also mirrored in a delayed (economic) development catch-up, resulting in an initially stagnating and subsequently only very slow reduction in income disparities. The spatially explicit scenario interpretation proceeds via two steps. Through a combination of decomposition and optimization methods, world regional scenario results are first disaggregated to the level of 185 countries. In a subsequent second step, national results are further disaggregated to a grid cell level, taking urbanization and regional (rural–urban) income disparities explicitly into account. A distinguishing feature of the spatially explicit scenario results reported here is that both methodologies, as well as numerical assumptions underlying the “downscaling” exercise, are scenario-dependent, leading to distinctly different spatial patterns of population and economic activities across the three scenarios examined.     

Land conservation and tenure security in Kenya: Boserup's hypothesis revisited

Land conservation technologies used by farmers are known to play an important role in improving farm incomes and household welfare in the long run. For this reason substantial investments have been made in research to improve agricultural technologies in various parts of the world, from the development of new crop varieties to new practices of land management. This paper explores the impact of land rights among other factors on adoption of soil and water conservation practices. The study further tests for Boserup's hypothesis (correlation between population density, land conservation and property rights) using panel survey data collected from farming households. The key findings of the paper are that property right regimes and population density affect both the decision to conserve land as well as the type of conservation practices used by farmers. The results further suggest a positive correlation between land tenure security and population density, thus supporting Boserup's hypothesis. The findings call for pursuit of both short-term and long-term policy measures that offer incentives for land conservation through government initiatives and participation of local communities.     

从人口规模看我国的就业问题

我国是世界上人口最多的国家,也是世界上劳动力资源最丰富的发展中国家,其就业压力也最大。近年来,失业问题已经引起了我国各级政府和社会各界的广泛关注。从人口规模角度探讨我国的就业问题,分析人口规模对就业的影响,这对实现我国经济发展战略,实现人口与经济、社会的协调发展都具有重要意义。     

老龄化社会和谐与保险行业创新

在建设和谐社会的过程中，必须面对我国人口老龄化的现实，从这层意义上说，建设我国和谐社会，也就是建设一个老龄化的和谐社会。因此，必须加快保险行业制度创新与产品创新步伐，主动适应社会发展要求，以保险业自身的创新及和谐进步来保障老龄化社会和谐建设。     

计量经济学应用研究的总体回归模型设定

本文从计量经济学应用研究中总体回归模型设定的任务和目标出发,通过对总体模型设定的研究目的导向、经济学理论导向、数据关系导向的分析与评价,提出总体模型设定的唯一性、一般性、现实性和统计检验必要性原则;最后,提出总体回归模型设定的"经济主体动力学关系导向"原则和框架。     

公共产品歧视性分配政策与城市人口控制

本文在一个二元经济框架内,通过一个改进的“亨利.乔治”模型,研究了转轨过程中的经济发展导向政府的城市人口控制问题。证明非歧视分配政策和任由城乡人口自由流动的政策组合并非一个有效率的户籍制度安排。不同主体之间在关于城市人口规模的控制上存在着利益差别,歧视性分配政策有助于缩小不同主体之间的利益差别。实行非歧视的公共产品分配政策同时对城市人口规模按照生产效率加以控制是现有体制下一个有效率的户籍制度安排。     

Patterns of growth in Chinese cities: Implications of the land lease

A special feature of China’s housing market is land use rights in the form of land leasehold contracts granted by the government. We consider an equilibrium model in which a representative developer may choose to redevelop existing centrally located housing or to develop new housing at the periphery of the city. We show that as the city grows, the land leasehold system results in the city center being developed less intensely and more land being used on the outskirts of the city when compared to a fee simple environment. Thus, cities in China are likely to be relatively more spread out, with city centers relatively older than would be the case with “fee simple” ownership. Our model suggests that excess residential land use is about 6 percent. In addition, compared with the ownership case, housing supply will grow more quickly in the near future, but more slowly later on during the transition of the Chinese economy. Parallel to the supply growth pattern, equilibrium price grows relative slowly in the near future, but more quickly later on. While we focus on residential uses, we believe our model can be applied to other land uses.