Residential mobility and the local context: Comparing long-term and short-term spatial trends of population movements in Greece

Residential mobility is a key dimension of population dynamics shaping urban growth and rural development at different spatio-temporal scales. Assuming spatial mobility as increasingly dependent on the intrinsic characteristics of local contexts, the present study investigates long-term and short-term population movements in a European country (Greece), in light of regional urbanization processes and socioeconomic development. A multidimensional analysis of indicators of residential stability and background variables was carried out with the aim at evaluating the influence of local contexts on more general processes of population mobility. Different typologies of spatial mobility associated to factors (directly or indirectly) dependent on demographic dynamics, economic performances and urban cycles were identified. The empirical findings of this study evidence (more or less traditional) paths of internal migration and a latent process of population relocation across metropolitan regions, together with more recent international migrations at both working and retirement age. While short-range population movements were the ultimate result of late suburbanization in Greece, medium- and broad-range mobility consolidated the country's divide in urban and rural areas, evidencing the attractive role of Athens. Spatial direction and intensity of population movements reflect complex socioeconomic transformations, whose knowledge provides innovative visions for a better understanding of future demographic dynamics in Mediterranean Europe.     

社会主义先进文化建设与人口文化健康发展的思考

文章着眼于山西人口计划生育的实际,从人口与计划生育的工作实际出发,就人口宣传教育方面如何加强社会主义先进文化建设,积极推进人口文化和生育文化的健康发展,全面营造良好的人口环境作了粗浅思考。     

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.     

Population ageing and inflation with endogenous money creation

This paper models a mechanism through which population ageing may induce a deflationary process. We propose an overlapping-generations model (OLG) with money created by credits (inside money) and intergenerational trade. The model links demographic factors, such as fertility rates and longevity, to prices. We show that lower fertility rates lead to smaller demand for credit and lower money creation, which in turn cause a decline in prices. Changes in longevity affect prices through real savings and the capital market. Furthermore, a few links between interest rates and inflation are addressed; they arise in the general equilibrium and are not thoroughly discussed in literature. Long-run results are derived analytically; short-run dynamics are simulated numerically.     

一场影响深远的错误批判——试述对马寅初《新人口论》的批判

1953年的人口普查引起我国著名经济学家马寅初的高度重视,他通过实地调查,于1957年提出《新人口论》,分析了我国人口增长同生产力发展的矛盾,从而提出控制人口的主张。但由于极左思潮的影响,《新人口论》遭到批判。各种批判文章将马寅初的《新人口论》和马尔萨斯的人口论挂钩,指责马寅初的《新人口论》是新马尔萨斯主义。这场错误批判产生了严重的后果,它把许多人口学家错误地打成右派,使我国人口理论的研究停滞,使计划生育工作受到严重挫折。     

Strategy-proof preference aggregation: Possibilities and characterizations

An aggregation rule maps each profile of individual strict preference orderings over a set of alternatives into a social ordering over that set. We call such a rule strategy-proof if misreporting one's preference never produces a different social ordering that is between the original ordering and one's own preference. After describing two examples of manipulable rules, we study in some detail three classes of strategy-proof rules: (i) rules based on a monotonic alteration of the majority relation generated by the preference profile; (ii) rules improving upon a fixed status-quo; and (iii) rules generalizing the Condorcet–Kemeny aggregation method.     

基于个体为本模型的中国碳排放核算模型构建

为合理测算中国碳排放总量, 提出了以单个人为基础的碳排放核算模型。个体碳排放量受其物质资本与人力资本、消费倾向与投资倾向影响,而计算中国碳排放总量还应考虑人口增长的影响。对个体资本投资倾向提出合理假设,进而构建人口增长模型。最后,根据各省GDP分布情况,赋予模型一个初始财富值,核算出中国碳排放总量。     

FOOD INSECURITY AND INSUFFICIENCY AT LOW LEVELS OF FOOD EXPENDITURES

In this study we investigate the external validity of the food insecurity and insufficiency measures—specifically, how these measures correlate with food expenditures—using the December 2003 Food Security Supplement of the Current Population Survey. We focus on a special segment of the population—households with low incomes and low food expenditures. If reports of food problems are based on a lack of food, reports should be nearly ubiquitous at the bottom of the expenditure distribution. We find, however, that this is not the case. We define and scale food expenditures several different ways and find that the reported incidence of food insecurity never rises above one‐half anywhere along the corresponding expenditure distributions, leading to concerns about the external validity of the measure.     

Forecasting the urban skyline with extreme value theory

The world’s urban population is expected to grow fifty percent by the year 2050 and exceed six billion. The major challenges confronting cities, such as sustainability, safety, and equality, will depend on the infrastructure developed to accommodate the increase. Urban planners have long debated the consequences of vertical expansion—the concentration of residents by constructing tall buildings—over horizontal expansion—the dispersal of residents by extending urban boundaries. Yet relatively little work has predicted the vertical expansion of cities and quantified the likelihood and therefore urgency of these consequences.We regard tall buildings as random exceedances over a threshold and use extreme value theory to forecast the skyscrapers that will dominate the urban skyline in 2050 if present trends continue. We predict forty-one thousand skyscrapers will surpass 150 meters and 40 floors, an increase of eight percent a year, far outpacing the expected urban population growth of two percent a year. The typical tall skyscraper will not be noticeably taller, and the tallest will likely exceed one thousand meters but not one mile. If a mile-high skyscraper is constructed, it will hold fewer occupants than many of the mile-highs currently designed. We predict roughly three-quarters the number of floors of the Mile-High Tower, two-thirds of Next Tokyo’s Sky Mile Tower, and half the floors of Frank Lloyd Wright’s The Illinois—three prominent plans for a mile-high skyscraper. However, the relationship between floor and height will vary considerably across cities.     

人口老龄化背景下法国养老金保险制度改革及其启示

本文首先介绍了法国养老金制度的现状;然后介绍了萨科齐政府养老金制度面临的挑战;紧接着介绍了2010年养老金改革法案的内容及历程;最后借鉴法国养老金制度改革的经验,总结出完善我国养老金制度的几点启示:避免社会保障碎片化格局;社会保障不能拖累经济发展;设计养老金制度必须考虑可持续性问题;鼓励社会各界参与养老保险改革。