叶尔羌河平原绿洲土地生态安全预警演变与时空格局分析

[目的]探索叶尔羌河平原绿洲土地生态安全预警问题及其时空格局变化,旨在为叶尔羌河平原绿洲土地生态安全及可持续利用提供科学的参考依据。[方法]文章运用PSR模型构建预警指标体系,采用熵值法测算各指标权重,对2000—2016年叶尔羌河平原绿洲土地生态安全警情格局进行综合分析,并利用GIS技术分析其2000年、2005年、2010年和2016年土地生态安全空间格局变化,最后运用障碍度模型探索其障碍因子。[结果](1)2000—2016年叶尔羌河平原绿洲土地生态安全综合预警指数总体呈上升态势,生态预警状态由"较不安全"转为"临界安全",警度亦由"重警"变为"中警"。(2)从空间格局来看,空间上各县域土地生态安全水平差异明显,研究初期西部地区土地生态安全状态优于东部地区, 2016年呈现出中部高、东北—西南部低的态势。(3)近17年叶尔羌河平原绿洲各县域土地生态环境状况有所改善,安全状态经历了"极不安全—临界安全—较安全"的发展历程。(4)影响土地生态安全的主要障碍因子包括单位面积耕地农药负荷、人口密度、单位面积耕地化肥负荷、土地垦殖率、人口自然增长率和单位面积耕地地膜负荷等。[结论]研究期间叶尔羌河平原绿洲土地生态安全得到明显的提升与改善,并在良好的方向发展。     

基于DEA方法的中国农业水资源利用效率研究

[目的]以我国各省市2008~2015年农业水资源利用效率为研究对象,探究我国农业水资源利用效率的规律与特点,并基于此提出促进农业水资源合理利用的建议。[方法]主要采用了文献研究法、统计分析法和数据包络分析(DEA)法。通过文献搜集我国各省市2008~2015年与农业水资源利用相关的数据,构建DEA模型,对我国近年来农业水资源利用效率进行评价。[结果]2008~2015年,我国农业水资源利用效率在0.80上下浮动。各省市农业水资源利用效率随时间变化趋势不同。甘肃和上海的农业水资源利用效率涨幅最大,年增长率分别为4.39%和2.74%;山西、江西以及陕西省的农业水资源利用效率整体趋于下降;浙江、湖南以及陕西和新疆的农业水资源利用效率有先上升后下降的特点,表现出明显的波动。此外,农业水资源利用效率区域分化明显。东部地区农业水资源利用效率一般高于0.80,中部地区位于0.60~0.80,西部地区农业水资源利用效率一般低于0.60。[结论]2008~2015年,我国农业水资源利用效率表现出一定的时间差异性和空间差异性。时间差异性:我国农业水资源利用效率一直处于较高水平并呈现逐年增长趋势,不同省份的农业水资源利用效率随时间变动趋势各异。空间差异性:东部地区农业水资源利用效率最高,中东部地区农业水资源利用效率甚至达到了最优,中部地区其次,西部省区农业水资源利用效率最低。农业水资源利用效率受当地政策、经济发展水平、农业发展水平、水资源总量和人口压力等因素影响严重,今后应针对不同地区采取不同措施解决实际问题。     

基于政府门户网站视角的中美预算公开信息比较与评价

互联网是政府信息公开的一种主要途径。基于政府门户网站这一公开渠道及网络信息传播特点,可以从专门性、全面性、详细性、动态性、便利性等不同角度,对美国和中国的201 1年度中央(联邦)预算公开信息进行比较。虽然近几年中国在预算公开方面取得了一定进展,但仍处在起步阶段,预算公开信息呈现典型的"碎片化"特征,缺乏制度性保障,与社会期望仍有较大的差距。因此,应以政府门户网站为主要公开渠道,提高中国政府预算公开信息的质量。     

无网上购物经验的消费者橱窗购物行为——基于交易成本视角的实证研究

本文基于交易成本经济学理论,应用结构方程模型,对我国无网上购物经验的消费者的橱窗购物行为进行研究。研究结果表明,在我国,无网上购物经验的消费者的橱窗购物行为受交易成本的影响很大。研究同时表明,交易成本与不确定性、资产专用性和信任度密切相关。如果消费者信任倾向低,在面对高不确定性和高资产专用性时,会感受到较高的交易成本。而当消费者面对高可靠性和详细的隐私政策时,则倾向于在网上购物中加大投入成本。     

大连城市居民周末休闲时间的利用特征

本文利用大连居民日常生活行为调查的结果,在比较居民工作日与周末休闲活动的基本特征基础上,从个人属性、社会属性和空间属性角度,对大连市居民周末休闲特征进行了较为详细的分析。分析中对居民社会属性与其休闲时间利用─—尤其是活动方式的选择──进行了相关分析,并引入时间地理学方法描画了居民周末活动路径,为城市休闲规划提供了基础知识。     

Has Switzerland Really Been Marked by Low Productivity Growth? Hours Worked and Labor Productivity in Switzerland in a Long‐run Perspective

This paper shows that previous work has understated Switzerland's performance in terms of labor productivity growth. First, available data on hours worked are incoherent and overestimate growth in hours worked. The paper therefore establishes a consistent series of total hours worked and its components covering 1950–2010, showing that Swiss labor inputs actually were stable from 1964 to 2007. Second, long‐term improvements in Switzerland's Terms of Trade indicate that quality improvements in Swiss exports might not be fully mirrored in growth of GDP and, hence, productivity growth.     

On the determinants of household debt maturity choice

This article jointly analyses a behavioural and a cultural concept to explain household debt portfolio choice. The behavioural approach explores the role of time preferences on household debt maturity in a theoretical model and a numerical analysis. We derive a positive relationship between the long-term discount factor δ and the optimal maturity of household loans. The cultural approach examines whether national culture is a reasonable predictor for household debt maturity. We show that culture is an important factor for households’ borrowing decisions and has even more predictive power than time preferences. Countries with higher scores on the Hofstede dimension of long-term orientation tend to have shorter household debt maturity. Time preferences incur a primarily mediating role, because the effect of national culture on the borrowing decision is reduced, as the long-term discount factor δ increases.     

Was the recent downturn in US real GDP predictable?

This article uses a small set of variables – real GDP, the inflation rate and the short-term interest rate – and a rich set of models – atheoretical (time series) and theoretical (structural), linear and nonlinear, as well as classical and Bayesian models – to consider whether we could have predicted the recent downturn of the US real GDP. Comparing the performance of the models to the benchmark random-walk model by root mean-square errors, the two structural (theoretical) models, especially the nonlinear model, perform well on average across all forecast horizons in our ex post, out-of-sample forecasts, although at specific forecast horizons certain nonlinear atheoretical models perform the best. The nonlinear theoretical model also dominates in our ex ante, out-of-sample forecast of the Great Recession, suggesting that developing forward-looking, microfounded, nonlinear, dynamic stochastic general equilibrium models of the economy may prove crucial in forecasting turning points.     

Is There a Causal Effect of Working Part‐Time on Current and Future Wages?

In this paper, I study the causal effects of part‐time work on current and future wages. To estimate these effects, I use a random effects model with a wage equation capturing the employment history and a dynamic multinomial probit component for the choice of employment status. Exclusion restrictions from the institutional context are exploited to support identification. The results suggest that working part‐time with few hours has a large causal effect on current wages, but more extensive part‐time work does not reduce current wages. However, both types of part‐time work lead to negative long‐term wage effects.     

Evaluation of the green technology innovation efficiency of China's manufacturing industries: DEA window analysis with ideal window width

Data Envelopment Analysis (DEA) window analysis with ideal window width is applied to evaluate the green technology innovation efficiency of 28 manufacturing industries in China during 2006–2014. The obtained results are compared with those calculated using the traditional DEA model, and convergence analysis of the efficiency is conducted. Five years is the obtained ideal window width and DEA window analysis with ideal window produces results closer to reality for China's manufacturing industry. The overall efficiency of the green technology innovation in the manufacturing sector is low following a wave-shaped curve – first decreasing, then increasing and decreasing again, with large inter-industrial differences. There are 8 high-, 14 medium- and 6 low-efficiency industries. A convergence trend in the green technology innovation efficiency within the 28 manufacturing industries exists, implying a catch-up effect between them.