资源环境约束条件下甘肃农业与农村经济可持续发展问题研究

在资源环境约束条件下解决农业与农村经济可持续发展的问题是当前西部农村社会发展中的重要课题之一。本文主要从甘肃省资源环境禀赋的现状出发,运用实证分析方法,解读了甘肃省在农业资源配置中存在的问题及其资源环境恶化对甘肃农业与农村经济可持续发展的影响水平,并进一步提出了在资源环境约束条件下促进甘肃农业与农村经济可持续发展建议和方法。     

大学生课外体育锻炼意识与行为的调查分析

采用问卷调查法、文献资料法和数据统计法,对地方院校大学生参与课外体育活动现状进行调查,探讨大学生课外体育锻炼活动的特点和规律。为培养大学生体育兴趣和终身体育意识,提高课外活动效果,促进高校体育教育的发展提供对策。     

自然资源会计的理论框架构想

本文旨在探讨自然资源资产的界定,并构建一个自然资源会计的理论框架以及分析其未来研究趋势。     

Instrumental variable estimation based on grouped data

The paper considers the estimation of the coefficients of a single equation in the presence of dummy intruments. We derive pseudo ML and GMM estimators based on moment restrictions induced either by the structural form or by the reduced form of the model. The performance of the estimators is evaluated for the non-Gaussian case. We allow for heteroscedasticity. The asymptotic distributions are based on parameter sequences where the number of instruments increases at the same rate as the sample size. Relaxing the usual Gaussian assumption is shown to affect the normal asymptotic distributions. As a result also recently suggested new specification tests for the validity of instruments depend on Gaussianity. Monte Carlo simulations confirm the accuracy of the asymptotic approach.     

The European refugee crisis and the natural rate of output

The European Commission follows a harmonized approach for calculating structural (potential) output for EU member states that takes into account labour as an important ingredient. This article shows how the recent huge migrants’ inflow to Europe affects trend output. Due to the fact that the immigrants immediately increase the working population but effectively do not enter the labour market, we illustrate that the potential output is potentially upward biased without any corrections. Taking Germany as an example, we find that the average medium-term potential growth rate is lower if the migration flow is modelled adequately compared to results based on the unadjusted European Commission procedure.     

Fiscal Equalization and Tax Enforcement

In many countries organized as federations, fiscal equalization schemes have been implemented to mitigate vertical or horizontal imbalances. Such schemes usually imply that the member states of the federation can only partly internalize (marginal) tax revenue before redistribution. Aside from the internalized marginal revenue, referred to as the marginal tax‐back rate, the remainder is redistributed. We investigate the extent to which state‐level authorities in such federation under‐exploit their tax bases. By means of a stylized model, we show that the member states have an incentive to align the effective tax rates on their residents with the level of the marginal tax‐back rate. We empirically test the model using state‐level and micro‐level taxpayer data, OLS regressions and natural experiments. Our empirical findings support the results from our theoretical model. Particularly, we find that states with a higher marginal tax‐back rate exploit the tax base to a higher extent.     

Effects of the structural change on transaction costs between North America natural gas spot markets

Threshold cointegration between market pairs before and after the potential structural break associated with the shale gas revolution is examined. Pairwise transaction costs differ between the pre- and post-break periods. During the post-break period, five of seven pairwise transaction costs decrease, while the remaining two pair-wise transaction costs increase relative to the pre-break period. Alterations in natural gas flows as the result of the shale gas revolution partially explain the changes in transaction costs.     

The effect of legal status on immigrant wages and occupational skills

Native and foreign-born workers with a high school degree or less education work in different types of occupations. This article exploits the 1986 Immigration Reform and Control Act to examine whether legal status causes immigrants to work in occupations that use skills similar to those of natives. Legal status decreases the manual skill intensity of immigrants’ occupations by about two percentiles. It increases communication skill intensity by a similar amount. This reduces the skill gap between Mexican-born and native-born American workers by 11–15%.     

海南岛自然生态系统服务价值评估

以卫星遥感影像为基础,运用"3S"技术,解译并统计了海南岛陆地自然生态系统的类型和面积,利用生态经济相关理论基础,评估计算出年海南岛陆地自然生态系统服务价值。结果表明,2008年海南岛自然生态系统服务价值约2198×108元,是当年全省GDP的1.5倍;森林生态系统的服务价值占四类生态系统(森林、草地、湿地和淡水)服务价值的81.77%,单位面积价值量达3260×104元/km2;自然生态系统在维持营养物质循环、水调节、大气调节等方面的间接使用价值约2076×108元,是直接使用价值的17.0倍。研究首次建立了针对海南岛陆地生态系统服务价值全面的评估体系,并在评估方法上择优、改进,对海南岛自然生态系统服务价值监测体系的构建及深入研究具有重要意义。     

自然保护地自然资源资产产权制度现状辨析

“建立以国家公园为主体的自然保护地体系”是党的十九大所提出的国家公园体制建设的新方向。实现自然保护地的有效保护管理是其重要内容，关键在于通过改革形成科学、合理的自然资源资产产权制度，而厘清自然资源资产产权制度的现状则是进行改革的前提。首先，对现行法律进行系统梳理，明确法律所认定的自然保护地中的自然资源类型。其次，从自然资源的产权种类及所有权改变、用益物权流转三方面总结了自然保护地自然资源资产的产权制度现状。再者，从各类自然保护地申报设立的条件和环保督查中反映出来的问题两方面入手分析了自然保护地的自然资源保护管理现状，从国家公园体制试点采取的措施出发分析了目前的改革探索，并提炼出自然保护地自然资源资产产权制度存在的四大问题，即自然资源资产产权的界定和要求较局限、自然资源所有权行使人虚位、公权与私权的利益协调机制不健全、改革探索中物权途径面临制度障碍。最后，从自然资源资产产权制度设计的角度提出了改革的4个方向。