环境规制、能源消费结构与雾霾——基于省际面板数据的实证检验

采用我国30省(市、区)2003—2012年面板数据,分析环境规制强度、能源消费结构与雾霾之间的关系。首先,以PM10浓度指标进行聚类,把30省(市、区)划分为高、中、轻三大污染地区。其次,面板单位根检验结果显示各变量是一阶单整I(1);Pedroni和Kao协整检验表明变量之间存在协整关系;FMOLS回归发现,全国总体环境规制强度与PM10浓度呈反方向变动,能源消费结构与PM10浓度呈同方向变动;高污染地区能源消费结构对PM10浓度产生正的影响,中、轻污染地区环境规制强度对PM10浓度产生负的影响。最后,提出了使用法律、经济手段加强环境规制,降低煤炭消耗比例、发展清洁能源等建议。     

港口物流业创新型研发人才集聚评价模型——基于长三角20个城市实证研究

创新型研发人才是宝贵的资源,其集聚水平的高低直接影响着经济的发展与社会的进步。论文在界定港口物流业创新型研发人才及总结人才集聚研究现状的基础上,建立港口物流业创新型研发人才集聚科学的指标体系,并以2010年长三角20个典型城市的数据为横截面进行研究,运用主成分分析法构建评价模型,得出长三角20个城市人才集聚水平的排名,并据此对20个城市进行聚类分析。研究发现：上海人才集聚水平远高于江浙两省;长三角城市群人才集聚水平呈圈层式发展;长三角各城市人才集聚水平的高低差异由五个子系统共同决定,其中经济和科研环境起着决定性作用。最后,针对港口物流业如何集聚人才、吸引人才,提出有指导性的行业人才集聚的对策建议。     

GMM and 2SLS estimation of mixed regressive,spatial autoregressive models

The GMM method and the classical 2SLS method are considered for the estimation of mixed regressive, spatial autoregressive models. These methods have computational advantage over the conventional maximum likelihood method. The proposed GMM estimators are shown to be consistent and asymptotically normal. Within certain classes of GMM estimators, best ones are derived. The proposed GMM estimators improve upon the 2SLS estimators and are applicable even if all regressors are irrelevant. A best GMM estimator may have the same limiting distribution as the ML estimator (with normal disturbances).     

Identification and estimation of econometric models with group interactions,contextual factors and fixed effects

This paper considers identification and estimation of structural interaction effects in a social interaction model. The model allows unobservables in the group structure, which may be correlated with included regressors. We show that both the endogenous and exogenous interaction effects can be identified if there are sufficient variations in group sizes. We consider the estimation of the model by the conditional maximum likelihood and instrumental variables methods. For the case with large group sizes, the possible identification can be weak in the sense that the estimates converge in distribution at low rates.     

跨国公司在华R＆D与中国企业技术创新

文章在一个由跨国公司和发展中东道国企业所构成的寡头垄断的产量竞争模型中,考察了跨国公司在发展中国家的R＆D活动对东道国自身企业的技术创新的影响,并最终发现技术溢出效应的强弱、技术转化水平的高低等因素都会决定这一影响的大小。在此基础上,文章提出了一些政策建议。     

政府R&D补助方式如何影响企业R&D投入?——来自A股医药制造业上市公司的证据

政府RD补助是否一定促进企业RD投入?针对这一问题,本文以区分政府RD补助方式作为切入点,从理论角度分析事前一次性RD补助、补贴率方式RD补助及事后奖励方式RD补助对企业RD投入的不同影响;并使用A股医药制造业上市公司2007~2013年面板数据进行实证分析。本文研究发现,只有补贴率方式和事后奖励方式RD补助显著促进了企业RD投入,其余补助方式对企业RD不存在显著促进作用。对样本按产权特征进行分组后,我们发现对于非国有样本,补贴率方式和事后奖励方式RD补助都显著促进RD投入;而对于国有样本,所有类型补助对公司RD投入皆无显著影响。本文的结论表明,政府应更多使用补贴率方式和事后奖励方式RD补助;企业产权特征是政府补助时值得考虑的因素。     

政府研发补贴方式对战略性新兴产业创新的影响机制研究

本文研究了政府研发补贴的不同发放方式对战略性新兴产业创新产生的不同影响机制。动态博弈模型分析指出,定额补贴由于不影响战略性新兴产业先行厂商的产品质量决策,所以在促进原始创新方面,它不如比率补贴有效。本文使用系统GMM方法估计了2009~2013年我国战略性新兴产业上市公司的动态面板数据,发现上市公司接受的定额研发补贴对其创新产出,即技术进步没有显著影响;这些上市公司上期的技术进步和当期研发投入会正向显著增加其创新产出。我国各级政府需要改变普遍使用的定额研发补贴方式,以比率研发补贴来代替定额研发补贴,从而提高战略性新兴产业的创新产出。     

Effects of scale economies and production seasonality on optimal hub locations: the case of regional fresh produce aggregation

Interest in supporting local and regional food systems is rising and food hubs have attracted considerable attention among Federal, State, and local policymakers. This study explores the problem of endogenous hub location in fresh produce value chains in the Northeastern United States. To overcome limitations in the literature, we incorporate the effects of economies of scale and production seasonality into our models. Three experimental models are designed to examine the effects of alternatively applying yearly, quarterly, and monthly data on model solutions. We explicitly assess how interactions of scale economies and seasonality influence the structure and spatial attributes of an optimal regional produce aggregation hub system. The three models generate marketed different solutions and in many respects they lead to different conclusions about developing local/regional supply chains. The monthly model allows for production seasonality and actual hub operation cycle frequency and thus leads to more efficient hub solution with rich policy implications.     

Food price increases and net food importing countries: lessons from the recent past

Recent increases in food and other commodity prices have highlighted concerns that many poor countries are net food importers and higher food prices would worsen their trade balances. In this article, we analyze the changes in food trade balances associated with the 32% increase in food prices from 2000/2001 to 2004/2005. We find a small deterioration in food trade balances of low‐income countries and an improvement in middle‐income countries. The deterioration is most severe for countries in conflict and small island states, so attention should be placed first on these countries and on a few very‐low‐income countries that are also vulnerable. Because low‐income countries as a group had much lower agricultural GDP growth rates than middle‐income countries, the answers to food vulnerability in low‐income countries should probably be addressed within the context of incentives for agricultural production.     

Does employment before marriage exert autonomy after marriage? Evidence on female autonomy from India

This paper examines the determinants of female autonomy using data from India. We model female autonomy for movement as well as economic decision-making using a summative index approach. Our contributions to the literature include a careful examination of the regional differences, tests of economic and sociological hypotheses on female autonomy and the use of pre-marriage autonomy measures in terms of employment status to determine post-marriage autonomy. Our results suggest that economic, sociological and pre-marriage autonomy factors explain female autonomy. Regional differences regarding the economic, sociological and pre-marriage autonomy factors play a role in determining female autonomy.