How to estimate market concentration given grouped data

A novel method is proposed of estimating market concentration for the census case in which firms are grouped into size classes and all that is known about the firms in each category is their number and aggregate size. The formula arises as a way of applying an alternative expression for the concentration ratio based upon the original and first moment size distributions of firms. The semi-parametric technique, which includes a method of interval as well as point estimation, is derived, applied and validated using actual and simulated data. It is anticipated that the estimator will be of use in competition analysis as well as in academic research.     

Flexibility at the Margin and Labor Market Volatility in OECD Countries*

We study the business‐cycle behavior of segmented labor markets with flexibility at the margin (e.g., just affecting fixed‐term contracts). We present a matching model with temporary and permanent jobs (i) where there is a gap in the firing costs associated with these types of jobs and (ii) where there are restrictions in the creation and duration of fixed‐term contracts. We show that a labor market with ``flexibility at the margin'' increases the unemployment volatility with respect to one that is fully regulated. This analysis yields new insights into the interpretation of the recent volatility changes witnessed in the OECD area.     

融资融券的操作与管理风险研究

融资融券是现代多层次证券市场的基础制度,有利于完善市场运行机制,但是在我国还是刚刚起步。本文对在融资融券交易制度下的实战操作和风险管理做了探讨。     

WTO反倾销协议日落复审条款及美国反倾销日落复审国内法之比较研究

依照WTO反倾销日落复审制度，反倾销税在征收5年后应该终止。但事实上我国的出口产品在美国被采取反倾销措施5年后，并没有因此规定而被停止征收反倾销税，这种无限期地实施反倾销措施偏离了世界贸易组织设置反倾销日落复审初衷。文章对WTO反倾销协议中的日落复审条款和美国反倾销日落复审的国内法进行了详细的分析，并指出美国反倾销日落复审的国内法存在违背WTO协议的可能，进而为我国企业提供有针对性的对策。     

大学英语视听教学探析

本文阐述了大学生在英语视听课中存在的主要问题,并对视听课堂教学环节提出了几点建议来培养学生的听能,提高大学生对听力材料的理解水平。     

Art works in international trade theory

Competitive International Trade Theory has frequently been criticized for its intensive use of diagrams (as opposed to more formal mathematics, such as calculus and algebra), prompted by its typical use of small dimensional models. This paper selects ten diagrams useful in capturing the essence of important trade theory and illustrating their usefulness even in higher-dimensional cases.     

国内服装制造企业库存管理的实证研究——基于沪深服装类上市公司1996-2008年的面板数据

文章对国内服装制造类上市公司库存水平的变动趋势及影响因素进行了实证研究。结果发现库存周转率与毛利率负相关,与固定资产比重正相关;销售下降时销售变动率对库存周转率的影响比销售增长更敏感。控制毛利率、固定资产比重、销售变动率及宏观经济因素后服装制造企业修正库存周转率逐年下降;公司绩效与库存周转率之间无相关关系,库存周转最慢和库存周转居中的公司投入资本报酬率高于库存周转最快的公司。     

全球价值链形成的动力系统及运行机制研究

全球价值链的形成可以归因于条件系统、动力系统和组织系统。全球价值链的动力系统主要包括促进全球价值链形成的各种动力及其各自在系统中所处的地位和相互作用关系。文章从力学和经济学的双重视角分析了全球价值链形成的动力机制,研究结论显示：全球价值链的形成必须依赖于一定强度的链接力。市场需求是全球价值链形成的动力引擎,一旦引擎启动后,就衍生出一对推动力与离散力。比较优势、规模经济、专业化经济是推动力的来源,而运输成本、协调成本及制度成本的增加构成了离散力的主要来源。     

The effect of immigrants on the extensive and intensive margins of trade

This study examines the impact of immigrants on the extensive and intensive margins of South Korean exports. Since trade data contain excessive zero trade flows, we adopt recently suggested Poisson and Gamma pseudo maximum likelihoods. ???Our finding shows that immigrant stock in South Korea has significant effect on both the extensive and intensive margins of South Korean exports. Immigrants’ network seems to decrease variable as well as fixed costs of trade.     

我国外汇保证金交易现状研究

外汇保证金交易因其以小博大、双向交易、外汇保值等特性在国际金融市场上得到了迅速发展,目前已是相对成熟的产品,交易量巨大。我国外汇保证金还处于起步阶段,经历了从1994年中央四部委发文禁止,到2006年交通银行破冰,再到2008年银监会全面叫停的发展过程。进入2009年,外汇保证金业务发展又有了新趋势,国内银行纷纷试探监管红线,境外大型外汇交易机构也加速进入国内市场。