国家高新区提高了城市创新力吗

以我国2001-2016年240个地级市作为样本，基于国家高新区这一准自然实验，利用复旦大学产业发展研究中心发布的2017年《中国城市和产业创新力报告》中城市创新指数数据，基于双重差分(DID)法，评估其对城市创新力的影响。研究发现：①国家高新区设立可以显著提高所在城市创新能力，并呈现出随时间逐渐增强的动态发展趋势；②高新区的设立对城市创新能力提高的作用受所在地区初始要素禀赋影响，对初始要素禀赋具有比较优势的地区创新能力提升的促进效应更显著，对不同地区、不同等级、不同规模城市及不同城市群产生差异化影响。结论表明, 应充分结合各地区禀赋条件，将高新区更多设立在要素禀赋具有比较优势的地区。     

经济开放与货币需求:国际金融风险及持币成本的测度

在中国开放经济体制下的基准货币需求模型中,本文将源于国际金融市场的持币成本设为遗漏潜变量,并构建特定的国际金融综合指数(CIFI)作为该潜变量的测度。借鉴机器学习与测度理论,本文利用对数误差修正模型提出了分步降维的CIFI构造算法,构造了长期CIFI和短期CIFI。结果表明,CIFI构造中的无监督降维步骤有助于减少高维金融数据中的冗余信息。实证分析发现,国际机会成本对中国货币需求具有规律性的前导影响,而在2007至2008年国际金融危机期间,央行的应急措施对长期CIFI所代表的非均衡冲击起到明显的阻截效果,对短期CIFI的影响基本是持续不变的。通过综合指数构造与宏观货币需求模型的算法连接,可以利用CIFI的构成结构从前导时间与影响强度两方面追踪冲击货币需求的国际金融风险的具体来源,这为宏观决策者监测国际金融市场提供了颇有规律的信息。在方法论上,本研究为如何利用模型监测国际金融市场影响宏观经济开辟了一条新路。     

险资股权投资的结构性改革研究*——基于险资投资的倒U型效应分析

保险资金作为重要的机构投资者能否发挥促进公司绩效提升的作用在已有研究和监管政策制定上都存在较大争议。本文以2005-2017年A股上市公司为研究样本，发现险资持股比例对上市公司绩效以及估值影响存在显著的倒U型曲线效应，相应机制研究表明险资持股通过显著影响两类代理成本的渠道发挥治理作用。在适度持股比例以下，险资增持能够降低被投资公司管理费用率和其他应收款占比，并提高资产周转率，从而降低两类代理成本；持股超过一定比例反而造成两类代理成本上升。险资持股比例变化对保险机构调研次数的影响则从公司治理参与角度印证了以上结论。对倒U型曲线效应的深入分析既有助于深化对机构投资者影响公司绩效的多重效应和机制的认识，同时为在金融机构层面落实金融供给侧结构性改革、增强险资服务实体经济能力提供参考。     

Do Air Quality Alerts Affect Household Migration?

This article examines the effect of air quality information on immigration and emigration of households in California counties by measuring the change in the number of air quality alert days. Based on panel data for 2000–2014, I find evidence suggesting that more frequent air quality alerts reduce the rate of population growth in a county by decreasing immigration of households. This is driven by “Unhealthy” air alerts, which signals weaker air quality than “Unhealthy for Sensitive Groups.” The negative impacts on immigration are larger for high household income counties and are strongest when there is a sharp increase in the number of air quality alerts.     

The impact of research collaboration on academic performance: An empirical analysis for some European countries

The aim of this paper is to investigate the impact of internal and external research collaborations on the scientific performance of academic institutions. The data are derived from the international SCOPUS database. We consider both quantity (the number of publications) and quality indicators (the field-weighted citation impact and the share of publications in the 10% most-cited articles) to evaluate universities' performance in some European countries (Germany, France, Italy, the UK and Russia). To this end, we develop a non-overlapping generations model to evidence the theoretical idea of research externalities between academic institutions. Moreover, we implement an empirical model to determine the extent to which the impact of internal and external collaborations on universities' performance is sensitive to the geographical dimension of the data.     

Dynamics of Child Malnutrition in Rural and Small‐Town Ethiopia

Improving the status of malnourished children, and preventing children from becoming malnourished, lies at the heart of several of the Sustainable Development Goals. While many cross‐sectional studies examine correlates of stunting, they largely cannot identify drivers of change in stunting. We use two waves of panel data from Ethiopia and incrementally larger sets of fixed effects to control for time‐variant observable characteristics and time‐invariant unobservable characteristics. After controlling for these potential confounders, our analysis reveals that many factors that are associated with stunting in the cross‐section do not impact stunting dynamics. We also estimate individual fixed‐effects regressions, separately, according to baseline stunting status. We find evidence suggesting that while improved societal conditions drive many children out of a stunted state, certain exogenous factors may lead previously healthy children to become stunted. Overall, policymakers and practitioners would be wise to consult research utilising both cross‐sectional and panel data analyses in order to more effectively target already stunted children as well as vulnerable children who may be at risk of becoming stunted.     

Investigating Treatment Effects of Participating Jointly in SNAP and WIC when the Treatment Is Validated Only for SNAP

The U.S. Department of Agriculture operates several food assistance programs aimed at alleviating food insecurity. We study whether participation in both participation in both SNAP and WIC alleviates food insecurity compared with participation in SNAP alone. We bound underlying causal effects by applying nonparametric treatment effect methods that allow for endogenous selection and underreported program participation when validation data are available for one program (treatment) but not the other. We estimate average treatment effects using data from the National Household Food Acquisition and Purchase Survey (FoodAPS). FoodAPS includes administrative data to validate SNAP participation. Information on local food prices allows us to construct a food expenditure‐based monotone instrumental variable that does not require a typical instrumental variable exclusion restriction. Under relatively weak monotonicity assumptions, we identify that the impact of participating in both programs relative to SNAP alone is strictly positive, suggesting that the programs are nonredundant. This evidence can support improved design and targeting of food programs.     

乌蒙山片区绿色减贫指数分析

[目的]通过分析2012年和2014年乌蒙山片区绿色减贫指数,评价该地区不同年份扶贫效果,这也为今后各项扶贫政策的实施提供理论参考。[方法]文章依据中国绿色减贫指数指标体系,从经济增长绿化度、资源利用与环境保护程度、社会发展能力和扶贫开发与减贫效果4个方面,以人均地区生产总值、单位地区生产总值能耗等27个因子作为评价指标,利用线性加权综合法分析2012年和2014年经济增长绿化度、资源利用与环境保护程度、社会发展能力和扶贫开发与减贫效果指标值,最终确定绿色减贫指数。同时,分析片区内各贫困县波动较大的第三产业增加值比重、单位耕地面积化肥施用量、城乡收入比和农村人均纯收入增长率等指标。[结果]2014年相比2012年,乌蒙山片区经济增长绿化度、资源利用与环境保护程度和扶贫开发与减贫效果指标值上升,社会发展能力指标值降低,绿色减贫指数提高了15.40%。各县第三产业比重均降低,但农村人均纯收入都有提高。四川省10个县单位耕地面积化肥施用量增加。四川省除叙永县和美姑县,贵州省除赤水市,片区内的各贫困县城乡收入比降低。[结论]2014年,乌蒙山区在落实国家扶贫规划上取得了较好的成效。但各县之间差距较大,在今后的扶贫攻坚中,需要从不同地区的实际情况出发,了解贫困类型和贫困程度,考察当地资源储备和环境现状,统筹区域发展。     

FREE VERSUS SECOND‐BEST ENTRY IN COURNOT OLIGOPOLIES WITH FIRM‐SPECIFIC NETWORKS

This paper endogenizes the number of firms in an industry with positive network effects, complete incompatibility, and firms that compete in quantity. To this end, we compare two possibilities: free entry and second‐best number of firms (the one that maximizes social welfare). We show that with business‐stealing competition, free entry yields, in general, more firms than the socially optimal solution. In addition, we find that by the nature of the industry with firm‐specific networks, total production may be greater or lower under free entry than with a regulator; moreover, some industries attain their maximum social welfare with a monopoly.     

The role of health,experience, and educational attainment in agricultural production: Evidence from smallholders in Burkina Faso

We apply parametric and nonparametric methods to data from smallholders in Burkina Faso and assess the role that human capital characteristics play in the agricultural production process. Our results point to the technology‐changing nature of health, education, and experience. However, effects are rather heterogeneous. The productivity elasticity of health is much larger for households in the lowest landholding quintiles, while returns to experience are larger for households in the upper quintile. In terms of policy implications, our results suggest that productivity can be stimulated through the allocation of expenditure to social services that enhance certain types of human capital. Interventions aimed at improving the health status of households with smaller landholdings could have particularly strong welfare effects.