Discrepancies between ex ante and ex post efficiency under identical subjective probabilities

Summary. Starr (1973) showed that, if people have different subjective probabilities, ex ante and ex post efficiency conflict. Conversely, under the simple preferences that he considered, the discrepancy between ex ante and ex post efficiency disappears when subjective probabilities are identical. Here I consider identical subjective probabilities, but more general preferences. First, risk attraction is admitted. Second, I dispense with the double requirement (dubbed IZU) of additive separability and state-independence of the utility of zero-date consumption, an unrealistic requirement when modeling the investment in durable goods. I find that, under IZU, and as long as ex post preferences satisfy the natural assumption of quasiconcavity (and satisfy some technical qualifications), an ex ante efficient allocation is indeed ex post efficient, but the converse is not necessarily true under risk attraction. If, on the other hand, IZU is violated, then one can have ex ante efficient allocations that are not ex post efficient, and vice-versa, even under risk aversion. Received: June 25, 1999; revised version: March 2001     

How many voters are needed for paradoxes?

Summary. This paper presents a general procedure for finding profiles with the minimum number of voters required for many important paradoxes. Borda's and Condorcet's classic examples are revisited as well as generalizations. Using Saari's procedure line, we obtain an upper bound for the minimum number of voters needed for a profile for which the Condorcet winner is not strictly top ranked for all weighted positional procedures. Also we give a simple upper bound on the minimum number of voters needed for a set of prescribed voting outcomes. In contrast to situations wherein small numbers of voters are needed, we consider paradoxes requiring arbitrarily large numbers of voters as well as large numbers of alternatives. Finally we indicate connections with statistical rank based tests. Received: April 18, 2001; revised version: May 25, 2001     

The lexicographic composition of abstract games

The lexicographic composition of reflexive and complete binary relations (which are often called abstract games) is studied. The necessary and sufficient conditions are obtained for a lexicographic composition of quasi transitive relations to be quasi transitive.The case of acyclicity of lexicographic composition of two relations is also investigated. Received: September 25, 2000; revised version: November 28, 2000     

浮息债券基准利率创新分析

浮息债券基准利率的选择直接决定了浮息债券的投资价值。中国目前浮息债券基准利率有一年期定期存款利率和7日回购利率两种。本文主要通过对两种基准利率的生成机制以及市场波动特征进行分析,重点讨论了不同基准利率浮息债券的融资成本以及浮息债券基准利率创新对中国商业银行证券投资管理带来的新的挑战。     

Learning for Innovation and the Skill Premium

The computer revolution took very long to pay off in productivity growth in the computer-using sectors. The relative wage of skilled workers, however, has risen sharply from the early days of the computer revolution onward. As skilled workers wages reflect their productivity, the two observations together pose a puzzle.This paper provides a micro-based explanation for the long diffusion period of the computer revolution. The general equilibrium model of growth zooms in on the research process and provides an explanation for sluggish growth with booming relative wages of the skilled. Technological progress in firms is driven by research aimed at improving the production technology (innovation) and by assimilation of ideas or principles present outside the firm (learning). A new General Purpose Technology (GPT) like the computer revolution generates an initial slowdown in economic growth and an increase in the skill premium.Acknowledgement I am indebted to Theo van de Klundert for suggestions and encouragement. Suggestions by Jan Boone, Bas Jacobs, Patrick Francois, Henri de Groot, Lex Meijdam, Niek Nahuis Sjak Smulders, Harald Uhlig and anonymous referees have contributed to the paper.     

Skill-Specific rather than General Education: A Reason for US–Europe Growth Differences?

In this paper, we develop a model of technology adoption and economic growth in which households optimally obtain either a concept-based, general education or a skill-specific, vocational education. General education is costly to obtain, but enables workers to operate new production technologies. Firms weigh the cost of adopting and operating new technologies against increased profits and optimally choose the level of adoption. We show that an economy whose policies favor vocational education will grow slower in equilibrium than one that favors general education. More importantly, the gap between their growth rates will increase with the growth rate of available technology. By characterizing the optimal Ramsey education policy we also demonstrate that the optimal subsidy for general education increases with the growth rate of available technology. Our theory suggests that European education policies that favored specialized, vocational education might have worked well, both in terms of growth rates and welfare, during the 1960s and 1970s when available technologies changed slowly. However, in the information age of the 1980s and 1990s when new technologies emerged at a more rapid pace, they might have contributed to an increased growth gap relative to the United States.     

亚洲石油大陆桥建设设想

本文提出了关于建设亚洲石油大陆桥设想的国际意义,以及我国参与建设的必要性,并构建了亚州石油大陆桥的基本框架,最后提出中国应采取的主要对策和措施.     

城市国民经济和社会发展规划战略环境评价研究——以武汉市为例

城市国民经济和社会发展规划编制是否科学．会直接影响到城市其他规划的科学性，对城市未来的发展及生态环境状况影响重大。本文论述了对城市国民经济和社会发展规划开展战略环境评价的必要性和重要性．并结合（《武汉市国民经济和社会发展第十一个五年总体规划纲要》探讨了我国城市国民经济和社会发展规划战略环境评价的技术思路和技术方法。     

论节约型社会的营销创新探析

营销活动对环境的变化是非常敏感的。在变化的环境下，营销活动必须有所创新，才能在市场中立于不败之地。我国政府将“建设资源节约型、环境友好型社会”作为基本国幕，标志着我国进入建设节约型社会时期。节约型社会建设中营销环境的变化，对企业营销活动提出了新的要求，企业营销应从观念、产品、渠道等方面进行创新以适应新的环境，形成企业新的竞争力。     

Competition with Congestible Networks

We analyse competition between two network providers when the quality of each network depends negatively on the number of customers connected to that network. With respect to price competition we provide a sufficient condition for the existence of a unique pure strategy Nash equilibrium. Comparative statics show that as the congestion effect gets stronger quantities will decrease and prices increase, under both Bertrand and Cournot competition. In an example with endogenous capacities it turns out that equilibrium capacities are at first increasing and then decreasing in the strength of congestion. Furthermore, capacities are higher under Cournot competition. Welfare comparisons between Bertrand and Cournot competition are unambiguous for fixed capacities, but may turn around for endogenous capacities.