基于空间计量方法的城镇化动力实证研究——以环洞庭湖区域为例

在参考Cobb-Douglas生产函数构建的城镇化动力理论模型的基础上,使用空间计量方法对2000～2009年环洞庭湖区域城镇化动力进行了实证研究,结果显示:区域经济发展总体水平对城镇化有显著的正向促进作用,但呈逐年下降趋势;固定资产投资及流通产业发展对城镇化的推动作用较大,但仍不稳定;人力资本投资对洞庭湖区域城镇化的作用尚不显著。因此,要改变当前环洞庭湖区域城镇化动力不充足、不稳定的问题和促进湖区从"粗放城镇化"向"新型城镇化"转换,就必须主动对接"长株潭"城市群、深化分工和夯实产业基础、加大固定资产投资、充分发挥流通产业的先导作用并高度重视人力资本积累。     

集中连片特困地区扶贫开发金融服务工作存在的问题及相关建议——以大兴安岭南麓集中连片特困白城片区为例

推进扶贫开发,缓解和消除贫困,是深入贯彻落实科学发展观,全面建设小康社会、构建和谐社会,最终实现共同富裕的本质要求,也是党和国家的重大经济发展战略。集中连片特困地区是全国扶贫对象最多、贫困发生率最高、扶贫工作难度最大的地区。2011年11月,中央扶贫开发工作会议出台了《中国农村扶贫开发纲要（2011-2020年）》,提出要把＂连片特困地区＂作为新时期扶贫开发主战场。如何构建多元化、全方位的金融扶贫工作体系,对于增强集中连片特困地区可持续发展能力,加快推进集中连片特困地区脱贫致富具有重大意义。     

基于SD模型的诸城市农业结构仿真优化研究

［目的］预测2017—2035年诸城市农业结构的变化趋势,对农业结构进行多情景优化仿真,提出优化调整建议。［方法］文章以山东省诸城市作为研究对象,将农业结构划分为种植、种养结合和加工休闲3个子系统,选取56个指标,运用多元统计回归分析等方法构建41个方程,建立农业结构系统动力学（System Dynamics,简称SD）模型,运用Vensim—PLE软件进行仿真优化分析。［结果］SD模型预测结果表明,到2035年,粮食作物播种面积1105万hm2,总产量8037万t,经济作物播种面积652万hm2,总产量15203万t; 生猪出栏量达到29615万头,家禽出栏量1105 231亿只,畜禽粪污利用率8792%; 农业总产值达到25132亿元,休闲农业产值6134亿元,食品加工业产值1 25263亿元。假设种植业生产中的农业科技投入增加2个百分点, 2035年粮食作物产量较优化前增加576万t; 经济作物产量较优化前增加2814万t; 假设有机肥施用补贴增加3个百分点, 2035年畜禽粪污利用率较优化前提高762个百分点; 假设农产品加工业的研发力度和科技投入增加1个百分点, 2035年食品加工产值较优化前增加73521亿元; 农产品加工业产值占农业总产值比值由优化前的325：1达到41：1。［结论］为进一步推进诸城市农业结构调整,迫切需要加大农业科技投入,完善有机肥扶持政策,培育种养结合新型经营主体,重点扶持培育加工龙头企业,发展现代化休闲农场,促进农业产业融合发展。     

Land pressures,the evolution of farming systems,and development strategies in Africa: A synthesis

Evidence assembled in this special issue of Food Policy shows that rising rural population densities in parts of Africa are profoundly affecting farming systems and the region’s economies in ways that are underappreciated in current discourse on African development issues. This study synthesizes how people, markets and governments are responding to rising land pressures in Africa, drawing on key findings from the various contributions in this special issue. The papers herein revisit the issue of Boserupian agricultural intensification as an important response to land constraints, but they also go further than Boserup and her followers to explore broader responses to land constraints, including non-farm diversification, migration, and reduced fertility rates. Agricultural and rural development strategies in the region will need to more fully anticipate the implications of Africa’s rapidly changing land and demographic situation, and the immense challenges that mounting land pressures pose in the context of current evidence of unsustainable agricultural intensification, a rapidly rising labor force associated with the region’s current demographic conditions, and limited nonfarm job creation. These challenges are manageable but will require explicit policy actions to address the unique development challenges in densely populated rural areas.     

Simulación de la tasa de reciclaje de productos electrónicos Un modelo de dinámica de sistemas para la red de logística inversa

Current trends in the development and innovation of information technologies and shorter life cycles of electronic products have resulted in the generation of large amounts of waste (e-waste) which can potentially cause environmental problems due to the toxicity of some of their components. The e-waste problematic has attracted the attention of governments, companies and consumers that look to identify strategies for the management and proper disposal of e-waste with the goal to protect the environment. This work uses the methodology of system dynamics to simulate how the rate of products returned by individuals and the amount of computers recovered in an open-loop reverse supply chain, varies under different scenarios. The simulated scenarios correspond to the possible combinations of five macro factors: rate of innovation and product life cycle, information available to consumers about e-waste recycling, legislation, e-waste programs structure along with diffusion and publicity efforts. The results of the simulation are relevant to identify over which factors it is convenient to intervene to increase the amount of recycled computers because this amount represents a reduction in the volume of e-waste and an enterprise opportunity to generate earnings from recycling computers.     

能源系统动力学应用研究综述

对系统动力学理论在国内外的发展过程以及其在不同领域的广泛应用进行研究,概括了能源系统动力学的实质是系统动力学理论与SD模型在分析各类能源问题的实证研究与应用,报告了能源系统动力学国内外研究现状,总结了系统动力学在能源领域的应用以及其对环境保护、经济发展、社会进步等方面的贡献,并在此基础上展望了能源系统动力学在大数据时代与数据挖掘及GIS等理论结合研究的方向.     

Household indebtedness in Korea: Its causes and sustainability

This paper investigates why household debt in Korea has increased so rapidly over the past decade and whether it is sustainable, adopting a multi-faceted approach which includes a time series analysis, a quantitative analysis based on household panel data, and an analysis using a debt dynamics equation derived from the household budget constraint. A regression analysis reveals that household debt growth has been significantly related to house price increases, banks’ lax attitudes toward household lending, and financial institutions’ favorable funding conditions. Also 70–80% of the total debt increase has been accounted for by high income or newly indebted households. The debt dynamics equation analysis shows that the rapid rise in the ratio of household debt to disposable income is attributable not only to the increase in household asset purchases but also to the dampened growth in disposable income and the reduced savings rate. The sustainability analyses indicate that Korean households’ debt sustainability is unlikely to deteriorate sharply within a short period of time unless two extreme scenarios, under which house prices decline by 5% a year over the next five years, or a significantly large macroeconomic shock similar to the 1997 crisis hits the economy, would be realized.     

Poverty in US Lesbian and Gay Couple Households

Poverty is a widely researched topic in economics. However, despite growing research on the economic lives of lesbians and gay men in the United States since the mid 1990s, very little is known about poverty in same-sex couple households. This study uses American Community Survey data from 2010 to 2014 to calculate poverty rates for households headed by different-sex versus same-sex couples. Comparing households with similar characteristics, the results show that those headed by same-sex couples are more likely to be in poverty than those headed by different-sex married couples. Despite that overall disadvantage, a decomposition of the poverty risk shows that same-sex couples are protected from poverty by their higher levels of education and labor force participation, and their lower probability of having a child in the home. Lastly, the role of gender – above and beyond sexual orientation – is clear in the greater vulnerability to poverty for lesbian couples.     

CAFTA-DR Effects on FDI Inflows,Growth, and Distribution of the Workforce in Costa Rica: A System Dynamics Approach

As regional trading arrangements have spread, enlarged, and deepened over the last decades, the study of the relation between trade agreements and foreign direct investment (FDI) still presents difficulties due to the multi-dimensional character of such relationships. This article attempts to shed new light on how some of the Central American Free Trade (CAFTA) policies will impact FDI inflows on the manufacturing and agricultural sectors in Costa Rica. Specifically, we look at how the growth and distribution of the workforce is affected by the treaty. The results show that the agreement provisions will have a positive effect on FDI. From these results it is possible to estimate that in the long run, the implementation of CAFTA has a higher probability of generating the intended benefits. System dynamics modeling is used in this article.