Minimum Quality Standards under Asymmetric Duopoly with Endogenous Quality Ordering: A Note

In this note, we revisit minimum quality standards (MQS) under a vertically differentiated duopoly. We generalize the model in Ronnen (1991) and Valletti (2000) by introducing asymmetry into the fixed cost of quality improvement and by explicitly taking into account the endogeneity of quality ordering. In the generalized model, we show that the results derived by Ronnen (1991) and Valletti (2000) are largely robust.     

Free Entry under Uncertainty

When focusing on firm’s risk-aversion in industry equilibrium, the number of firms may be either larger or smaller when comparing market equilibrium with and without price uncertainty. In this paper, we introduce risk-averse firms under cost uncertainty in a model of spatial differentiation and show that the impact of uncertainty will increase the number of firms in an industry. With increased uncertainty, the risk premium of the marginal buyer increases by more than the risk premium of the average buyer, so that the price increases by more than the risk premium. When turning to the free entry game, we find that the market generates too many firms.     

Effect of credible quality investment with Bertrand and Cournot competition

We show how credible revelation and ability to commit to quality choice effect equilibrium qualities and welfare when product market is either Bertrand or Cournot competition. We show that results depend on the type of competition but not generally on the cost of quality function. We show that with Bertrand competition, the equilibrium qualities are lower with credible commitment. Competition is moderated and producer surplus is higher and consumer surplus lower. With Cournot competition, higher quality will be better but lower quality will be worse with credible commitment. Consumer surplus is always greater with credible commitment and if cost does not increase too quickly with quality, producer surplus will also increase. Thus credible commitment is a collusive device with Bertrand competition but it can improve social welfare with Cournot competition. Received: February 8, 2000; revised version: February 14, 2002 RID="*" ID="*" The idea of this paper originated in the weekly workshops of Mordecai Kurz at Stanford. I am forever in debted to Mordecai and fellow students – Luis Cabral, Peter DeMarzo, John Hillas, Michihiro Kandori, Steve Langois, Patrick McAllister, Steve Sharpe, Peter Streufert, Steve Turnbull and Gyu-Ho Wang – for their criticism and encouragement. I also benefited from comments from Yi-Heng Chen, Jin-Li Hu, Kala Krishna, Jinji Naoto, Thomas J. Prusa, and Shyh-Fang Ueng at various later stages of this work. Last but not least, I am grateful for the detailed comments of the referee.     

中国粮食生产区域分化特征和成因的实证研究

对中国在1990年和2002年粮食生产的区域分化状况进行统计分析的结果表明,工业化和城市化的发展,以及农产品市场形成条件下,稻米生产的区域分散特征、小麦生产的区域集中特征以及玉米播种面积的集中和生产产量的分散特征日益明显。计量检验显示,人均承包经营耕地面积和种植业收入比率是影响粮食生产区域分化的最主要的两个因素。     

农户过度放牧行为产生原因分析--来自黑河流域肃南县的农户调查

我国草地资源位居世界第二位,但目前退化非常严重,已经成为牧区生态环境保护和经济发展的主要制约因素。导致草地退化的原因多种多样,自然因素是不可调控因素,并且在近50年内并非是导致草地大面积退化的主要因素,实际上,人为因素才是最为主要的因素,其中过度放牧是最主要因素之一。农户作为草地使用和经营行为的微观主体,其行为可直接或间接地响应所有管理行为和制度的最终效应。通过针对肃南县草地退化进行的农户问卷调查进行详细剖析,并结合有关统计资料,尝试从农户角度阐释过度放牧行为产生的内在机制,认为农户的支出需求增加、收入的增幅减缓与缺乏稳定的收入预期、收入渠道单一以及生态支付意愿不高是导致农户过度放牧行为产生的根本原因。     

农民工的社会网络变迁

采用系统模式研究了进城农民工的社会网络重构过程,指出随着谋生方式由农业生产向非农产业的转移,进城农民工正在逐步建立起以业缘关系为基础的新的社会纽带,并使之成为其社会网络的重要组成部分.这些由进城农民工一手构建的社会关系网络正在成为他们在城市生活中赖以生存和发展的重要资本.     

Racing in two dimensions

In this paper we study an industry in which there is an ongoing sequence of R&D races between two firms. Firms are engaged in product innovation. Products are horizontally and vertically differentiated. There are two key characteristics/dimensions to products, and the level at which these are embodied in products can be increased by R&D. At each time firms can spend R&D on improving their product in one or both dimensions. We allow the possibility of economies scope — so R&D undertaken in one dimension can spillover to the other. The question we are interested in is whether a firm that is ahead in a single dimension but behind in another will focus all its R&D effort in the area in which it is ahead (product specialisation), or whether it will try to do R&D in both dimensions in the hope that it might get ahead in both and end up with a superproduct that dominates in both characteristics. The outcome of this R&D competition determines a Markov transition probability matrix determining the evolution of the industry. We show that when the R&D technology is characterized by constant returns then the only steady-state outcome is one in which the economy stays forever in a position in which one firm produces a super-product and the other gives up doing R&D altogether. This outcome is unaffected by the degree of economies of scope. When the R&D technology is characterised by decreasing returns, then the industry will visit all states and so will exhibit both product specialisation and superproduct dominance at various times. Now the extent of economies of scope matters and we show that the greater the extent of economies of scope, the less likely is the industry to exhibit product dominance, and the more likely it is to exhibit product specialisation.     

RECENT DEVELOPMENTS IN THE THEORY OF NATURAL MONOPOLY

Abstract. This paper examines two important recent developments in the theory of natural monopoly, or more generally the theory of market structure. The first is a series of papers, involving Baumol with various co-authors, investigating the theory of industry structure, whilst the second is particularly associated with the names of Shaked and Sutton, and the relationship they develop between product differentiation and industry structure. The paper surveys and to some extent contrasts these two new approaches.
Baumol et al. 's contribution is seen to be in the area of clarifying the concept of natural monopoly, refining the definitions of multiproduct costs, and developing a notion of social efficiency applicable to industries where economies of scale are important. Shaked and Sutton employ a new definition of natural monopoly unrelated to market size and utilize information about consumers'income distributions to develop their notion of vertical product differentiation and natural oligopoly.     

中国劳动力市场户籍分割与企业人力资本投资的作用

我们运用2004年中国9省(市)企业员工培训和继续学习调查数据,验证中国劳动力市场存在户籍分割,并分析企业人力资本投资,即在职培训对处于不同层次劳动力市场的员工收入增长、职业发展的影响。得出以下结论：(1)中国存在由户籍制度造成的劳动力市场分割特征,农民工主要处于次要劳动力市场。(2)户籍对于员工参与企业在职培训以及培训的收益率都有显著影响；在其他条件相同情况下,城镇户籍员工比农民工的在职培训参与率和收益率都显著更高。(3)在职培训对于提高农民工收入具有显著的正的影响。(4)此前培训(进入本单位前接受的培训)对于农民工进入主要劳动力市场具有显著作用。     

中部农区农户打工地城镇规模类型——以河南省三个样本村为例

对农户打工地城镇规模类型的研究是认识农民工流动规律的重要内容.基于入户调查数据,采用多值逻辑回归模型和有序逻辑回归模型,以河南省三个样本村为例,对中部农区农户打工地城镇规模类型进行了研究.研究发现,农户打工地主要集中于省城、深圳经济特区、乡镇和地级市,而在县城打工的人较少;农户对打工地城镇规模类型的选择与打工距离密切相关;家庭代数、村经济发展水平和关系网络是影响农户打工地城镇规模类型选择的重要因素.