设立国家级贫困县能提升当地农民收入水平吗——基于2007~2016年中国296个县面板数据的实证研究

中国自1986年实施贫困县制度以来，国家级贫困县的设立是否能够以及在多大程度上提升了当地农民实际收入水平，需要进行系统科学的实证检验。基于双重差分倾向得分匹配法（PSM-DID），利用2007~2016年全国6个省份296个县的面板数据进行实证研究发现，国家级贫困县的设立非但没能有效提升当地农民实际收入水平，反而对其有持续的负效应。进一步研究发现，贫困地区第二、三产业的发展能够有效提高当地农民实际收入水平，然而贫困县政策并未促进当地产业结构的优化；政府通过正向干预农产品价格能有效增加农民实际收入。从研究结论的政策含义讲，立足贫困户推进精准扶贫、通过招商引资带动有效投资，以及优化县域产业结构，对于提升贫困县的农民收入具有重要现实意义。     

Residential mobility and the local context: Comparing long-term and short-term spatial trends of population movements in Greece

Residential mobility is a key dimension of population dynamics shaping urban growth and rural development at different spatio-temporal scales. Assuming spatial mobility as increasingly dependent on the intrinsic characteristics of local contexts, the present study investigates long-term and short-term population movements in a European country (Greece), in light of regional urbanization processes and socioeconomic development. A multidimensional analysis of indicators of residential stability and background variables was carried out with the aim at evaluating the influence of local contexts on more general processes of population mobility. Different typologies of spatial mobility associated to factors (directly or indirectly) dependent on demographic dynamics, economic performances and urban cycles were identified. The empirical findings of this study evidence (more or less traditional) paths of internal migration and a latent process of population relocation across metropolitan regions, together with more recent international migrations at both working and retirement age. While short-range population movements were the ultimate result of late suburbanization in Greece, medium- and broad-range mobility consolidated the country's divide in urban and rural areas, evidencing the attractive role of Athens. Spatial direction and intensity of population movements reflect complex socioeconomic transformations, whose knowledge provides innovative visions for a better understanding of future demographic dynamics in Mediterranean Europe.     

财权和事权相匹配关系研究

在政府间财政关系中,财权和事权的匹配是主要的财政关系之一,明确财权和事权的划分,保证财权和事权相匹配是我国财税改革的关键。然而,当前政府间财权和事权划分不明确,导致了财权上移、事权下放等问题,没有达到真正意义上的匹配。文中在此回顾各方意见,总结政府间财权与事权的理论依据和存在的问题,并对现阶段的改革对政府间财权事权关系的影响做了简要评述。     

A context-based service matching approach towards functional reliability for industrial systems

ABSTRACT

As service-oriented computing is commonly used in industrial systems to deal with the continually changing business environment, matching processes with existing services becomes one of the most important phases in constructing, integrating and optimizing information systems. The precision of semantic service matching becomes a critical factor in ensuring the correctness of functionalities in system processes. However, the dependability of semantic service matching cannot be warranted in complex contexts. To improve semantic service matching for industrial systems, a context-based semantic service matching approach named ‘Process-Based service MatchMaker’(PBMM) is proposed in this paper. It selects the suitable services for the process from candidate services through taking the dependencies of related services process into consideration.     

2008年3季度银行间市场运行报告

2008年3季度,货币市场利率运行基本平稳,季末利率有所上扬,3个月shibor大幅回落;银行间债券综合指数大幅上涨;人民币兑美元汇率中间价上下震荡,本季度人民币对美元小幅升值0．60％;人民币外汇掉期报价贴水大幅收窄。     

市场运行平稳,人民币持续走强 2007年银行间外汇市场运行报告

2007年银行间外汇市场运行平稳。与2006年相比,外汇远期交易量增长六成,外汇掉期交易量增长三倍多,外币对交易量增长近两成,外币拆借交易量下降近五成。2007年,人民币兑美元和港币继续保持升值趋势,兑日元和英镑升值、兑欧元贬值。与2006年年末中间价比,2007年末人民币兑美元汇率中间价累计升值6.90%。与2005年汇改当日中间价比,人民币累计升值13.31%。     

Time series momentum and moving average trading rules

We compare and contrast time series momentum (TSMOM) and moving average (MA) trading rules so as to better understand the sources of their profitability. These rules are closely related; however, there are important differences. TSMOM signals occur at points that coincide with a MA direction change, whereas MA buy (sell) signals only require price to move above (below) a MA. Our empirical results show MA rules frequently give earlier signals leading to meaningful return gains. Both rules perform best outside of large stock series which may explain the puzzle of their popularity with investors, yet lack of supportive evidence in academic studies.     

Evaluation of the profitability of quality labels in rural tourism accommodation: a hedonic approach using propensity score matching

In recent years, quality labels for the Spanish tourism sector have been developed as part of a competitive strategy focused on the differentiation of the product. Given this development, it is interesting to analyse the profitability of quality labels for the accommodation owners and managers. In particular, this article calculates the profitability of a rural tourism quality label. Through the use of the hedonic price approach, the market valuation of the quality label for rural self-catering cottages is obtained. This valuation is subsequently compared with the expenses incurred by establishments in achieving the quality label. In order to address the usual methodological problems associated with the endogeneity, prior to application of the hedonic approach, the propensity score matching is used. The results indicate that possessing a quality label has a positive impact on the profitability of rural tourism.     

Bias-corrected estimates of reduction of post-surgery length of stay and corresponding cost savings through the widespread national implementation of fast-tracking after liver transplantation: a quasi-experimental study

Background: Fast-tracking is an approach adopted by Mayo Clinic in Florida’s (MCF) liver transplant (LT) program, which consists of early tracheal extubation and transfer of patients to surgical ward, eliminating a stay in the intensive care unit in select patients. Since adopting this approach in 2002, MCF has successfully fast-tracked 54.3% of patients undergoing LT.

Objectives: This study evaluated the reduction in post-operative length of stay (LOS) that resulted from the fast-tracking protocol and assessed the potential cost saving in the case of nationwide implementation.

Methods: A propensity score for fast-tracking was generated based on MCF liver transplant databases during 2011–2013. Various propensity score matching algorithms were used to form control groups from the United Network of Organ Sharing Standard Analysis and Research (STAR) file that had comparable demographic characteristics and health status to the treatment group identified in MCF. Multiple regression and matching estimators were employed for evaluation of the post-surgery LOS. The algorithm generated from the analysis was also applied to the STAR data to determine the proportion of patients in the US who could potentially be candidates for fast-tracking, and the potential savings.

Results: The effect of the fast-tracking on the post-transplant LOS was estimated at approximately from 2.5 (p-value?=?0.001) to 3.2 (p-value?Conclusion: The fast-track program was found to be effective in reducing post-transplant LOS, although the reduction appeared to be less than previously reported. Nationwide implementation of fast-tracking could result in substantial cost savings without compromising the patient outcome.     

The Productivity Effects of Worker Mobility Between Heterogeneous Firms

We analyze the effect of worker inflows on establishments’ productivity, using German data. Previous studies for other countries have found positive effects of hiring workers from superior (more productive or higher paying) firms. Ranking establishments by their median wage, we find that inflows from inferior establishments seem to increase hiring establishments’ productivity. Further empirical analyses suggest our findings are due to a positive selection of such inflows from their sending establishments. These workers might have to find a better job match in order to advance their careers, an interpretation supported by the finding that the effect is driven by workers with short tenure at their previous employer. Our findings reflect the increasingly assortative pattern of worker mobility in Germany found in a related strand of literature.