基于多源遥感数据的马铃薯收入保险应用研究

目的 研究面向创新型农业保险业务中缺少及时准确的第三方作物产量结果用于灾损理赔的问题。引入多源卫星遥感测产技术,识别测产关键因子,构建产量模型。方法 文章运用多元线性回归分析方法,选取山西省马铃薯主产县岚县为研究区,计算基于Sentinel2影像的植被指数,结合气象卫星数据与实测单产数据,筛选关键因子,建立马铃薯单产遥感测产经验模型。结果 采用GF-2影像分割与Sentinel2长势时序识别岚县马铃薯种植面积为8 477.65hm²,精度检验Kappa值为0.72。保险公司岚县承保马铃薯面积2 476.37hm²,承保覆盖率为29.21%。测产结果显示,马铃薯单产与区域关键期地表温度参数相关性较好,岚县遥感测产获得平均单产为13.76 t/hm²,实地测产获得平均单产为14.06 t/hm²,误差百分比为2.13%,分乡镇平均误差百分比为22.97%,基本满足理赔业务需求。在2018年保险期结束后一周内,保险公司启动快速赔付,支付赔款125.29万元,赔付率48.46%。结论 遥感测产具有大范围、时效性好、可靠性高等特点,能够迅速为创新型保险产品提供测产理赔结果,提高理赔效率,保障农民收入。     

北京市农村居民点用地特征与整理方向分析

研究目的：研究不同类型农村居民点的整理方向。研究方法：综合分析法,归类分析法和GIS方法。研究结果：（1）最新数据表明北京市农村居民点总计有3803个行政村,总用地面积1141 km2,空间特征差异显著;（2）依照规划城镇建设用地范围边界和规划控制范围边界,可以将居民点区分为圈内居民点、环内居民点和环外居民点;（3）三类农村居民点存在显著的不同特点,整理方向不同。研究结论：北京市农村居民点用地规模偏大,需要按照农村居民点的区位分布与特征采取差异化的整理模式,提升北京市农村居民点土地利用效率。     

Assessing the effects of financial heterogeneity in a monetary union a DSGE approach

The aim of this article is to analyze how financial heterogeneity can accentuate the cyclical divergences inside a monetary union that faces technological, monetary, budgetary and financial shocks. To this purpose, this study relies on a two-country Dynamic Stochastic General Equilibrium model, where the two countries are supposed to be differently sensitive to the bank capital channel. The model allows us to demonstrate how a given symmetric shock causes cyclical divergences inside a heterogeneous monetary union. On this point, it allows reproducing some stylized facts recently observed in the Euro Area. Moreover, it appears that the more heterogeneous the union, the larger the effects of financial asymmetries on the transmission of shocks. Finally, we show that a common monetary policy contributes to worsen cyclical divergences, in comparison with monetary policies that would be nationally conducted.     

“1＋1＋1”的教学改革模式——中职计算机专业分方向教学的探讨

从中职计算机专业的现状出发，为了培养出适应社会需求的实用型技术人才，实现中职学校的计算机教育事业又好又快发展，文章阐述了计算机专业分方向教学的设想，提出了“1＋1＋1”的教学改革模式。     

Sequential auctions with randomly arriving buyers

We analyze a dynamic market in which buyers compete in a sequence of private-value auctions for differentiated goods. New buyers and new objects may arrive at random times. Since objects are imperfect substitutes, buyers? values are not persistent. Instead, each buyer?s private value for a new object is a new independent draw from the same distribution.We consider the use of second-price auctions for selling these objects, and show that there exists a unique symmetric Markov equilibrium in this market. In equilibrium, buyers shade their bids down by their continuation value, which is the (endogenous) option value of participating in future auctions. We characterize this option value and show that it depends not only on the number of buyers currently present on the market and the distribution of their values, but also on anticipated market dynamics.     

农村义务教育闲置资产产权界定问题探讨——基于陕西省的调查统计

明确界定农村义务教育闲置资产产权是实现闲置教育资源再利用的起点。由于农村义务教育投资结构复杂,现行法律法规和政策规定空泛、相互冲突,导致闲置资产产权界定困难。应借鉴国有企业产权界定模式,按照依法界定、分类确权的原则,构建所有权与使用权、处分权分离的农村义务教育闲置资产产权界定体系。     

Human capital accumulation and the intertemporal elasticity of substitution of labor: How large is the bias?

I consider two different skill accumulation technologies, learning by doing and Ben-Porath type training. The effect of human capital accumulation in the form of learning by doing is to increase the labor supply elasticity estimate by a factor of 2.1 relative to the estimate that ignores human capital accumulation. The results are similar for the Ben-Porath type training technology, although the estimate of the bias is somewhat higher.     

The real puzzle of blackmail: An informational approach

The “puzzle” of blackmail is that threats to reveal private information that would be harmful to someone in exchange for money are illegal, but revelation is not. The resolution is that concealment of information about product quality impedes the efficient operation of markets, whereas revelation promotes it. The real puzzle is why possessors are not naturally inclined to sell to uninformed parties, who value the information more than would-be blackmail victims. The answer has to do with the public good qualities of information, which create an appropriability problem in transactions with uninformed parties. The paper also discusses incentives to acquire compromising information.     

Testing for serial correlation and random effects in a two-way error component regression model

In this paper, we test the existence of serial correlation and random effects in a two-way error component regression model with panel data. Under moment conditions alone, we suggest several easily implemented tests based on the parameter estimators for artificial autoregressions modeled by the differences in residuals. Under the null hypotheses, the tests for serial correlation are two-sided and asymptotically chi-square distributed, whereas those for random effects are one-sided, and are asymptotically standard normally distributed variables. Moreover, these methods can also be used similarly to construct tests for both serial correlation and individual effects jointly, whether or not time effects are present. The proposed tests are able to detect local alternatives that are distinct from the null at the parametric rate. Monte Carlo simulations and real data applications are carried out for purposes of illustration.     

Monetary business cycle accounting

This paper investigates the quantitative importance of various types of distortions for inflation and nominal interest rate dynamics by extending business cycle accounting to monetary models. Representing various classes of real and nominal distortions as ‘wedges’ in standard equilibrium conditions allows a quantitative assessment of those distortions. Decomposing the data into movements due to these wedges shows that distortions generating movements in TFP and wedges in equilibrium conditions for asset markets are essential. In contrast, wedges capturing the effects of sticky prices play less important role. These results are robust to alternative implementations of the accounting method.