Remote sensing-based detection of agricultural land losses around Greater Cairo since the Egyptian revolution of 2011

Over the last four decades, the loss of agricultural land has been observed in Egypt at high rates. However, the highest rates of losses have occurred since the January 25th revolution in 2011. Greater Cairo (GC), which is the largest metropolitan in Egypt, has witnessed a massive loss of agricultural land since the 2011 revolution. However, until now, no study or official report has revealed the volume of agricultural land losses in this region. This study quantifies agricultural land losses around the GC using Landsat satellite images from 2010 and 2018. Supervised classification was performed using the maximum likelihood algorithm in QGIS software. A post-classification comparison method was applied to detect the land use/land cover changes between the classified images; then, the loss of agricultural land was quantified using Arc GIS software. Visualizations of the gains and losses in agricultural land and the spatial trends of agricultural land losses were created using TerrSet software. The results show that 9600 ha of agricultural land were converted to urban use during 2010–2018, which means that the annual rate of agricultural land loss has tripled and now reaches approximately 1200 ha per year. Decay of executive authority, rapid population growth, real estate market speculation and fragmentation of agricultural land were the main driving factors of agricultural land losses during this period. The results of this research may help decision makers understand the current high rate of agricultural land loss. Hence, appropriate strategies may be adopted to prevent future losses of this valuable land.     

The factors influencing the profitability of leased land on dairy farms in Ireland

The Republic of Ireland possesses a land market that is constrained by minimal sales each year, less than 1%. In an effort to capitalise on milk quota abolition and to increase dairy production, a suite of tax incentives has recently been introduced in the Republic of Ireland to encourage land mobility and long-term leasing among Irish dairy farmers. Using Irish Farm Accountancy Database Network (FADN) data from 2011–2017 to examine this, a Heckman sample selection model explores two aspects; (i) the factors that influence a farmer’s decision to rent, or continue renting, land and (ii) the profitability of dairy farmers renting in land. We find self-selection into the rental market is driven by farm traits that include a high level of hired labour, the presence of a successor, intensive farming practices and dairy discussion group membership. The results show that rental agreements assist farms in achieving economies of scale. The findings provide evidence to support government intervention such as tax incentives for renting out land and knowledge sharing discussion groups.     

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.     

新疆农村产业融合发展研究

现运用面板回归模型结合产值贡献度的方法评价了新疆农村产业融合度,结果表明,新疆农业与农产品加工业融合度、农业与农业服务业融合度均较低。通过地理信息可视化表达发现,新疆农村产业融合度且存在明显的区域差异。最后,结合新疆农村产业融合发展所面临的困境,提出了需要完善农业教育服务体系;培育区域特色品牌;加强对各种利益联结方式的监督引导等建议。     

Employment Dynamics and Linkages in the Rural Economy: Insights from Senegal

Evidence on rural wage employment is thin and lacks nuance for different employment sources, insights on dynamic effects, and an understanding of the channels of effects. We assess conceptually and empirically the direct and indirect welfare effects of entry and continuation in different types of wage employment in rural Senegal. Using panel data, fixed effects and first-difference estimation, we show substantial positive welfare and linkage effects. We find that participation in wage employment increases per capita income by 143%, and reduces poverty, poverty gap and food insecurity by, respectively, 63%, 89% and 48%. While the direct effect on income is larger for non-agricultural and contractual wage employment, the indirect income effects through self-employment are more pronounced for agricultural and casual wage employment. Our results imply that job creation is important for rural development, that wage employment in agriculture can lead to considerable growth multiplier effects, and that synergies exist between large-scale and small-scale agriculture.     

区际产业转移关联溢出与产业高质量发展——对电子设备制造业的实证检验

基于我国区际产业转移大背景，使用1999-2016内地年30个省市、27个二位数工业行业数据定量测度区际产业转移，选择产业关联较强的电子设备制造业为研究对象，使用投入产出法识别关联产业、测算其关联产业溢出，利用2004—2016年内地28个省市面板数据构建模型对关联产业溢出效应与电子设备制造业转移的关系、产业转移中的关联产业溢出与电子设备制造业高质量发展的关系分别进行了实证检验。研究发现：①2014年中国工业空间基尼系数出现拐点，总体工业由之前的分散转移转为新的集中转移，而电子设备制造业仍处在向中部地区和西南地区集聚的分散转移中；②电子设备制造业转移中的产业关联溢出效应确实存在，且促进了电子设备制造业生产效率的提高和产业高质量发展；③产业转移中第三产业关联溢出效应对电子设备制造业分散转移的作用高于工业，但工业的关联溢出对电子设备制造业生产效率提升的作用明显高于第三产业。     

“高校—企业”技术转移对企业创新绩效的影响——来自经验取样法的证据

为探讨现代企业与高校之间技术转移对企业创新绩效的影响，立足我国高科技上市公司，以经验取样法为研究范式，以高管与高校之间技术转移体验及创新成效为对象，展开连续15周日记研究，结果发现：“高校—企业”技术转移会积极影响企业创新绩效，规划性博弈与功利性博弈具有中介作用，技术吸收能力具有调节作用。由此证明，在“高校—企业”技术转移合作中，企业技术吸收能力水平在历经组织间博弈后，将显著调节由技术转化而形成的创新绩效增幅。建议相关企业主动开展创新合作，并通过均衡性博弈机制完善自身技术吸收体系，实现“高校—企业”技术转移“双赢”初衷。     

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.     

中国健康资本内生折旧率估算及成因分析

"健康中国"战略背景下,准确估算健康资本折旧率对把握我国人口健康资本动态变化具有重要意义。在经典的健康资本需求框架内,正式引入年龄、环境与健康投资的异质性,扩展构建健康资本内生折旧率模型。基于永续盘存法基本原理,结合精算模型与生命表数据,对不同年龄、性别和风险假设下我国居民健康资本折旧率进行估算与分析。研究发现,我国居民健康资本折旧率存在明显的年龄差异与性别差异:中青年阶段折旧率缓慢提高、老年阶段加速上升;男性健康资本折旧率始终高于女性。随着人口老龄化程度加深,年龄对健康资本折旧率的影响下降,健康投资的影响则持续增强。提高健康投资回报率,是降低折旧率进而提高我国人均健康资本存量的关键。     

新时期农业科技与金融融合的示范园模式与“公司+农户”模式探索

农民如何依托土地脱贫增收成为我国农业发展的关键问题。农业科技与金融的融合是家庭联产承包责任制下提升农业产出效率的有效手段。通过创新农业经营主体，建立政府引导、市场主导的“示范园模式”与“公司+农户”模式加强农业科技与金融融合；构建完善的试验-示范技术扩散体系，帮助农民进行技术模仿，提升农业技术能力；结合金融扶持，帮助农民提升对接市场技术的能力，提高土地产出效率是促进农民脱贫增收的有效途径。