Convergence and approximation results for non-cooperative Bayesian games: Learning theorems

Summary LetT denote a continuous time horizon and {G ^t :tT} be a net (generalized sequence) of Bayesian games. We show that: (i) if {x ^t : tT} is a net of Bayesian Nash Equilibrium (BNE) strategies for G^t we can extract a subsequence which converges to a limit full information BNE strategy for a one shot limit full information Bayesian game, (ii) If {x ^t : tT} is a net of approximate or _t-BNE strategies for the game G^t we can still extract a subsequence which converges to the one shot limit full information equilibrium BNE strategy, (iii) Given a limit full information BNE strategy of a one shot limit full information Bayesian game, we can find a net of _t-BNE strategies {x ^t : tT} in {G ^t :tT} which converges to the limit full information BNE strategy of the one shot game.We wish to thank Larry Blume, Mark Feldman, Jim Jordan, Charlie Kahn, Stefan Krasa, Gregory Michalopoulos, Wayne Shafer, Bart Taub, and Anne Villamil for several useful discussions. The financial support of the University of Illinois at Urbana-Champaign Campus Research Board is gratefully acknowledged.     

世界经济2006年的回顾与2007年的展望

2006年的回顾一、尽管原油价格高涨,2006年的世界经济仍然取得高增长去年(2006年)的世界经济在2005年以来的原油价格暴涨的影响之外,又加上有禽流感的困扰,经济形势稍有暗淡,但其增长率预计仍会继2005年的5.3%(实际增长率。     

The economics of networks

I analyze the salient features of networks and point out the similarities between the economic structure of networks and the structure of vertically related industries. The analysis focuses on positive consumption and production externalities, commonly called network externalities. I discuss their sources and their effects on pricing and market structure. I distinguish between results that do not depend on the underlying industry microstructure (the ‘macro’ approach) and those that do (the ‘micro’ approach). I analyze the issues of compatibility, coordination to technical standards, interconnection and interoperability, and their effects on pricing and quality of services and on the value of network links in various ownership structures. I also briefly discuss the issue of interconnection fees for bottleneck facilities.     

Spatial patterns of poverty in Vietnam and their implications for policy

This study examines the geographic distribution of poverty in Vietnam by applying small area estimation methods to household budget data and population census data. The resulting district-level poverty estimates suggest that the incidence of poverty is highest in the remote northern and central highlands and lowest in the south-east and in large urban centres. However, mapping the density of poverty reveals that most poor people do not live in the poorest districts but in the two lowland deltas, where poverty incidence is intermediate. The policy implications of these findings present an important trade-off between targeting poor areas and poor people that can only be resolved with better information on the relative costs of delivering different programmes and their expected impact. Existing government estimates of poverty at the district level are not closely correlated with our poverty estimates, perhaps because of regional variation in their methods of collecting poverty data.     

Inequality and Income Distribution in Global Value Chains

Global value chains (GVCs), led by transnational corporations (TNCs), have reshaped the world division of labor over the past two decades. GVCs are pervasive in low technology manufacturing, such as textile and apparel, as well as in more advanced industries like automobiles, electronics, and machines. This hierarchical division of labor generates wild competition at the lower value-added stages of production, where low wages and low profit margins prevail for workers and contract manufacturers in developing countries. At the top of the hierarchy another kind of competition prevails, centered on the ability to monitor and control intellectual property rights related to innovation, finance, and marketing. We argue that GVCs have had crucial effects on income inequality and the appropriation of rents in modern capitalism.     

Economic forecast quality: information timeliness and data vintage effects

This paper investigates the impact of the timeliness of information releases and data vintage variation on economic forecast quality. Specifically, using a set of 63 key US economic series, we provide a concise measure of the forecast accuracy associated with use of economic activity indices with different publication lags. A forecasting model based on an economic activity index that is subject to a short publication lag (viz. the Aruoba-Diebold-Scotti index) is more efficient than competing models. Moreover, if this publication lag advantage is removed (by artificially imposing a publication lag restriction comparable to that of a competing indicator) this efficiency largely disappears. The final part of the analysis employs a novel (simulation-based) method of assessing the impact of data vintage variation on forecast accuracy, and finds that the results are somewhat sensitive to such variation.     

VOTING AND SOCIAL PRESSURE UNDER IMPERFECT INFORMATION

We develop a model in which costly voting in a large, two‐party election is a sequentially rational choice of strategic, self‐interested players who can reward fellow voters by forming stronger ties in a network formation coordination game. The predictions match a variety of stylized facts, including explaining why an individual's voting behavior may depend on what she knows about her friends' actions. Players have imperfect information about others' voting behavior, and we find that some degree of privacy may be necessary for voting in equilibrium, enabling hypocritical but useful social pressure. Our framework applies to any costly prosocial behavior.