异质性企业贸易理论研究综述

本文回顾了异质性企业贸易理论的模型构建与发展演进,归纳了当前国外的实证研究成果,最后还对该理论在中国的应用与争论进行了总结,因此相对全面地涵盖了此领域国内外的最新发展情况.本文的目的是使国内学者对此问题能形成较全面的认识,从而为将来该领域的研究提供理论基础与研究思路.通过对现有文献的梳理可发现,尽管异质性企业贸易理论在广度和深度上都取得了一定程度的发展,但还存在一些问题尚未解决,如企业生产率的内生化,市场结构的设定,以及企业动态调整等都有待进一步深入研究.     

异质性企业理论的研究综述——基于异质性出口固定成本的最新动态

国际贸易理论与实证的研究越来越多地开始关注企业层面的进出口行为,异质性企业理论应运而生,并成为国际贸易的最新理论前沿之一。基于Melitz(2003)的理论研究,诸多学者对其模型进行了拓展,并衍生出许多分支。目前最新的文献已经突破了Melitz(2003)中企业只存在生产率单方面异质性的假设,引入了生产率和出口固定成本两方面的异质性,并探讨了其对企业出口行为的联合影响。本文主要针对异质性生产率、固定成本与企业出口行为之间的关系进行文献梳理,对比和分析相关研究的方法和主要结论,并从理论研究和经验研究两个方面阐述该领域的最新发展成果。最后,文章提出了已有研究的不足之处以及未来可能的研究思路。     

Melitz异质性企业贸易模型

Melitz的异质性企业贸易模型是新新贸易理论中最基本的模型,第一次将企业异质性作为模型的一个基本假设,通过模型的分析得出了高生产率企业选择出口,低生产率企业只服务国内市场的结论,很好的契合了之前的实证研究的结果。文章对Melitz模型进行了简单的推导,然后介绍了中国的生产率悖论现象,并对其原因进行了简单的思考。     

出口贸易、企业异质性和生产率:一个比较优势的分析框架

引入比较优势理念分析贸易与行业生产率增长之间的关系,构成企业异质性视野下出口贸易影响生产率的机理。通过数理模型构建出口贸易、比较优势与生产率之间关系的模型,并通过企业微观数据和行业层面数据对此关系进行实证检验。     

企业异质性、贸易自由化与环境污染

本文将企业的"排污—减排"决策引入基于拟线性需求系统的异质性企业垄断竞争模型,以研究贸易自由化对企业以及总体污染排放的影响。研究发现:在固定排污税率下,贸易自由化会增加全球总产出,但可能降低全球总污染排放,从而引致经济效益与环境效益的"双赢"。然而本文也发现这种情况只在初始排污税率较低之时成立。此外,在内生化的排污税率下,本文发现在一定参数下,最优的排污税率在贸易自由化以后应该上升。     

企业异质性、贸易自由化与市场扭曲

即使没有任何政策干预,市场本身的不完全也可能导致扭曲。本文在企业异质性框架下,构建包含Behrens类型需求结构的垄断竞争一般均衡模型,研究贸易自由化对市场扭曲程度的影响。通过比较静态分析,发现贸易自由化(市场规模扩张或者贸易成本下降)并没有减缓市场扭曲,这是因为,贸易自由化导致市场均衡福利和社会最优福利上升幅度相同。此外,随着一个经济体平均生产率的上升,会出现市场均衡福利上升和市场扭曲程度加剧并存的局面。进一步研究发现,理论模型得到的一般性结论同样适用于中国。本文的政策含义是,产业政策和贸易政策应该协调使用;随着一个经济体平均生产率的上升,产业政策的重要性加强。     

国外异质性厂商贸易理论研究综述

异质性厂商贸易理论代表了国际贸易理论最新发展趋势,研究的是微观经济主体--厂商的贸易和投资行为与自身特征的关系.厂商的市场进入方式与其生产率水平是相对应的,出口和贸易自由化能够提高行业生产率,汇率变化、贸易政策和产业集聚对厂商出口具有重要的影响,厂商进入出口市场前后存在自我选择效应和出口中学习效应,这两种效应都导致厂商生产率提高,最终生产率最高的厂商将以对外直接投资的方式进入国际市场.     

异质性企业贸易理论的起源与发展

本文旨在系统性地探究异质性企业贸易理论的起源与发展过程。首先对促使该理论诞生的实证挑战从企业的选择性出口、市场进入成本、资源再分配三个方面进行了综述;然后指出该理论发展的两条脉络和各自的理论基础,并在此基础上从平均生产率和贸易利得两个角度阐述了异质性企业贸易理论和新贸易理论之间的紧密联系,二者最大的差别便在于对边际生产成本的处理上,前者以边际成本的异质性替代企业的异质性,后者则忽略了企业之间的异质性。同时,针对国内学者的一些认识,本文也提出了自己的看法。     

理解R&D投入回报之谜:引入不确定性、非线性和企业异质性

既有研究发现企业R&D投入的回报不高甚至为负,这与R&D投入对经济增长具有重要作用的直觉背道而驰.其原因在于传统以知识资本模型为基础的研究,其估计的是平均R&D投入回报,平滑掉了R&D投入回报的企业异质性.文章建立了结构估计模型正式处理了R&D投入回报的不确定性、非线性以及企业异质性.与既有结构模型的区别在于,文章在模型中考虑了溢价的企业异质性,并明确处理了影响企业需求的因素.研究结果表明:R&D投入的回报确实是不确定的和非线性的,从而具有十分明显的企业异质性;个别企业的R&D投入回报甚至可以高出平均回报数倍,这足以为企业提供很强的R&D投入激励.R&D投入回报的企业异质性是理解平均意义上R&D投入回报较低与宏观层面R&D投入对经济增长具有重要作用的现实并存的钥匙.因此,我们有充分的理由相信,R&D投入及由此带来的生产率改善,能够成为新常态下推动中国经济持续发展的主要力量.     

异质性企业贸易理论的政策含义

通过回顾国际贸易理论与政策的演变,归纳出异质性企业国际贸易发展的特征事实,从多维视角探讨异质性企业贸易理论的政策含义。政府有关部门应该将贸易政策制定和评估的基点落实在企业层面,采取措施降低企业"走出去"的固定成本,重视关于贸易扩展边际的政策,有效识别企业出口贸易中的国内含量,提高企业的自主创新能力,认真权衡贸易政策制定的成本。     

Foreign direct investment,international trade,and firm heterogeneity

We present an asymmetric model with firm heterogeneity and foreign direct investment (FDI) from a developed country to a developing country. We found that the successful entry firms could be sorted from highest to lowest according to productivity as reimport firms, FDI firms, export firms, and domestic firms. We also found that FDI decreases (increases) the gross national income of the developed (developing) country, but it can either increase or decrease the world income according to the level of the relative propensity to spend. In addition, we demonstrated that FDI influences welfare through variations in average price, national income, and the number of types of goods.     

Product differentiation, firm heterogeneity and international trade: Exploring the Alchian–Allen effect

In a model of international trade with horizontally differentiated goods, increasing returns and monopolistically competitive markets, this paper proposes that the degree of differentiation in a product mix–defined as the ratio of the number of varieties to the total value of imports–can be regarded as another aspect of quality. Furthermore, this paper draws a parallel to the Alchian–Allen effect and shows that, when firms are heterogeneous in either fixed or variable costs, the degree of differentiation is increasing in per unit transportation costs.     

Firm heterogeneity in TFP,sectoral innovation and location. Evidence from Italy

Sectoral and territorial specificities affect a firm’s capabilities of being productive. While there is a wide consensus on this, a quantitative measure of these effects has been lacking. To this end, we combine a data-set of Italian firms with some meso regional and sectoral variables and apply a cross-classified model that allows for a clear distinction between firm, region-specific and sector-specific effects. After observing a marked TFP heterogeneity across firms, the paper addresses the issue of understanding how much differences in firms’ productivity depend on regional localisation and sector specificities. Results refer to 2004–2006 and have three aspects. First, they confirm that the main source of firm variety is mostly due to differences revealed at individual level. Secondly, we find that the sector is more important than location in explaining firms’ TFP. Lastly, the results show that firm TFP increases when it belongs to more innovative sectors. Similarly, companies get benefits from belonging to sectors where there is a high proportion of firms using R&D public support and a high propensity to collaborate in innovative projects.     

贫困陷阱的微观机制与实证研究述评

近年来,一批发展经济学家在吸收早期贫困陷阱理论合理内核的基础上,借助现代经济学新的理论与方法,将贫困陷阱问题的研究从宏观层面推进到微观层次、从抽象的理论阐释推进到精细的实证分析,并在此过程中拓展了贫困陷阱问题的研究范围。本文以述论结合的方式梳理这一研究领域的新进展,并在发展经济学学科发展史的视野中审视贫困陷阱理论、展望进一步的研究方向。     

Fixed export cost heterogeneity, trade and welfare

Recent literature on the workhorse model of intra-industry trade has explored heterogeneous cost structures at the firm level. These approaches have proven to add realism and predictive power. This paper presents a new and simple heterogeneous-firms specification. We develop a symmetric two-country intra-industry trade model where firms are of two different marginal cost types and where fixed export costs are heterogeneous across firms. This model traces many of the stylized facts of international trade. However, we find that with heterogeneous fixed export costs there exists a positive bilateral tariff that maximizes national and world welfare.     

Incumbent heterogeneity in creative destruction: a study of three Dutch newspaper organisations

With a study of three Dutch newspaper organisations, we identify four dimensions along which incumbent response to discontinuous change may differ: response timing (early or late), size of commitment to the new business (big or small), progression of commitment to the new business (continuous or intermittent), and approaches to bridging the capability gap (internal development, strategic alliance, or acquisition). These response strategies are neither mutually exclusive nor static, and their relative focus differs over time as well as across incumbents. Such inter-temporal and cross-sectional variations in response strategies are influenced by various incumbent-specific characteristics and shaped by interrelated contingencies internal or external to incumbents.     

Compensation payments for habitat heterogeneity: Existence, efficiency, and fairness considerations

Compensation payments for voluntary conservation measures have become an important tool for biodiversity conservation worldwide. Each year substantial financial resources are spent on such measures, particularly in the context of agri-environmental schemes. In Europe, a debate has started on whether this money is spent effectively. In response to this debate it has been suggested that a portfolio of measures leading to habitat heterogeneity be implemented. Although payments for heterogeneous conservation measures have been analysed in the literature, it has never been questioned that payments can be designed in a way that encourages enough land users to carry out each conservation measure within a portfolio of measures. The purpose of this paper is to demonstrate that such payments do not always exist. Moreover, in cases where payments for habitat heterogeneity exist the payment scheme may require overcompensation of the land users, posing a limit to both efficiency and fairness considerations.     

A hybrid production structure in trade: theory and implications

In models of pure theory of international trade, no unique production structure is dominant. By grafting a specific factor structure onto a Heckscher–Ohlin framework, in a hybrid general equilibrium production model, this paper presents theoretical results with implications such as: (a) the relative price increase of a traded goods sector might have expansionary or contractionary output effect depending on factor intensities; (b) uniform primary-factor augmenting technical progress in the intermediate inputs sector might lead to a decline in the output of one of the sectors; (c) favorable relative price effect in one sector will lead to a drop in the return to the specific capital type depending on the grafted production structure. The proposed framework is useful for explaining stylized facts related to wage inequality, deindustrialization and export-processing, which have a great policy relevance for trade and development.     

Recurrent unemployment,welfare benefits and heterogeneity

The objective of this paper is to investigate the causes of the recurrences of individuals in unemployment during benefit periods. So as to attain this objective, we use administrative data from the Spanish Employment Agency to estimate a duration model with multiple spells that allows for unemployment state dependence through lagged unemployment duration in order to distinguish the heterogeneity and scarring effects. We find that an increase in the duration of previous unemployment benefit periods lengthens the expected duration of future unemployment benefit periods. True state dependence and heterogeneity, intensity of job search and local labour market conditions are among the elements that explain this unemployment state dependence.