Clever agents in adaptive learning

Saez-Marti and Weibull (J. Econom. Theory 86 (1999) 268) investigate the consequences of letting some agents play a myopic best reply to the myopic best reply in Young's (J. Econom. Theory 59 (1993) 145) bargaining model, which is how they introduce “cleverness” of players. I analyze such clever agents in general finite two-player games and show Young's (Individual Strategy and Social Structure, Princeton University Press, Princeton, NJ, 1998) prediction to be robust: adaptive learning with clever agents does select the same minimal curb set as in the absence of clever agents, if their population share is less than one. However, the long-run strategy distribution in such a curb set may vary with the share of clever agents.     

Bargaining and markets: complexity and the competitive outcome

Rubinstein and Wolinsky (Rev. Econ. Stud. 57 (1990) 63-78) consider a simple decentralised market game in which agents meet randomly or voluntarily and bargain over the terms of trade. They show that any individually rational price can be sustained as a sequential equilibrium even though the model has a unique competitive outcome. Here, I consider Rubinstein and Wolinsky's model and show that if complexity costs of implementing strategies enter players’ preferences, together with the standard payoff in the game, then every equilibrium is stationary/Markov and induces the unique competitive price. Thus, I demonstrate that aversion to complexity may provide a justification for the competitive outcome.     

Farsighted network formation

This paper studies a model of dynamic network formation when individuals are farsighted: players evaluate the desirability of a “current” move in terms of its consequences on the entire discounted stream of payoffs. We define a concept of equilibrium which takes into account farsighted behavior of agents and allows for limited cooperation amongst agents. We show that an equilibrium process of network formation exists. We also show that there are valuation structures in which no equilibrium strategy profile can sustain efficient networks. We then provide sufficient conditions under which the equilibrium process will yield efficient outcomes.     

Bidding for the future: signaling in auctions with an aftermarket

This paper considers auctions where bidders compete for an advantage in future strategic interactions. When bidders wish to exaggerate their private information, equilibrium bidding functions are biased upwards as bidders attempt to signal via the winning bid. Signaling is most prominent in second-price auctions where equilibrium bids are “above value.” In English and first-price auctions, signaling is less extreme since the winner incurs the cost of her signaling choice. The opportunity to signal lowers bidders’ payoffs and raises revenue. When bidders understate their private information, separating equilibria need not exist and the auction may not be efficient.     

黄龙洞旅游开发对洞内生态环境和人的影响研究

通过对黄龙洞年内不同季节定点测定，同时与对旅游影响还不大的龙王洞对比测定，作者发现黄龙滑滑内空气CO2浓度的明显变化主要受客流量的影响。旅游旺季和黄金周客流量急剧增长带来的洞内空气CO2浓度大幅度增长，有利于岩溶作用，但洞内黑暗、高湿、低温的生态环境，对洞内工作人员身体健康有害。洞穴内岩溶景观的变化，主要受漫长的自然岩溶过程的影响，与洞内开发旅游活动的关系不大，但与洞顶山地植被保护状况有密切关系。     

Endogenous lifetime and economic growth

Endogenous mortality is introduced in a two-period overlapping generations model: probability of surviving from the first period to the next depends upon health capital that is augmented through public investment. High mortality societies do not grow fast since shorter lifespans discourage savings; development traps are possible. Productivity differences across nations result in persistent differences in capital-output ratios and relatively larger gaps in income and mortality. High mortality also reduces returns on education, where risks are undiversifiable. When human capital drives economic growth, countries differing in health capital do not converge to similar living standards, ‘threshold effects’ may also result.     

Structural Decomposition Analysis of Physical Flows in the Economy

Many environmental problems can be attributedto the extraction and emissions of physicalsubstances. Increasing our understanding of theeconomic and technological driving forcesbehind these physical flows can contribute tosolving the environmental problems related tothem. The input-output framework is a usefulsetting in which to integrate detailedinformation about economic structure andphysical flows. In this article a specificmethod in input-output analysis is reviewed,namely Structural Decomposition Analysis (SDA).It is based on comparative static analysis,which decomposes historical changes of a policyvariable into determinant effects. SDA has beenapplied, for example, to analyze the demand andtechnological driving forces of energy use,CO₂-emissions and various other pollutantsand resources. This article examines thetheoretical aspects of structuraldecomposition, in particular those concerningphysical flows and environmental issues.Furthermore, the article includes an extensivesurvey of empirical studies.     

Commitment and choice of partner in a negotiation with a deadline

This paper analyses the effects of partially revocable endogenous commitments of a seller in a negotiation with a deadline. In particular, we examine when commitment is a source of strength, a source of inefficiency and when it does not affect the bargaining outcome at all. We show that when commitment possesses a minimum amount of irrevocability this crucially determines the bargaining outcome. In the bilateral bargaining case, commitment becomes a source of inefficiency since it causes a deadline effect. In the choice of partner framework, however, the deadline effect disappears and there is an immediate agreement and, moreover, commitment becomes a source of strength since it increases the seller's equilibrium payoff by triggering off competition between the buyers.     

Norwegian Emissions of CO2 1987–1994 A Study of Some Effects of the CO2 Tax

Several countries have introduced taxes on fossil fuels with the aim of reducing atmospheric emissions, partly because of local environmental goals (SO₂, NO_x) and partly to participate in a global effort to reduce emissions of greenhouse gases. Many macroeconomic studies, based on both global and national models, have been made of how emissions can be reduced with the help of taxes and the consequent reduction in GDP following the introduction of such taxes. Norway has had a CO₂ tax for five years, thereby providing a unique opportunity to evaluate the effects of this tax on emissions. The paper provides a counterfactual analysis of energy consumption and emissions if no CO₂ taxes had been introduced, compared with the actual situation in which such taxes exist. The effect of a CO₂ tax on oil consumption, and thus CO₂ emissions is studied on the basis of partial economic models for various sectors of the Norwegian economy. The study indicates that the CO₂ tax has had an impact on CO₂ emissions in Norway.     

The Effect of Protest Votes on the Estimates of WTP for Use Values of Recreational Sites

Contingent valuation studies are often characterized by a considerable number of protest responses, which may cause selectivity bias on the final estimates for WTP. Sample selection models can detect and – if necessary – correct selectivity bias. In economic applications where the relevant dependent variable is continuous, sample selection models are generally estimated using Heckman's 2-step method rather than the FIML estimator. Either method has its own drawback: computational complexity for the FIML method, susceptibility to collinearity problems for the 2-step method. Using data on valuation of forest resources for recreational use, we analyse the performance of the two estimators. In this application, given the presence of some collinearity, the FIML is preferred to the 2-step method. A procedure is outlined to deal with selectivity problems in similar settings.