Regional, national, and spatially explicit scenarios of demographic and economic change based on SRES

We report here spatially explicit scenario interpretations for population and economic activity (GDP) for the time period 1990 to 2100 based on three scenarios (A2, B1, and B2) from the IPCC Special Report on Emissions Scenarios (SRES). At the highest degree of spatial detail, the scenario indicators are calculated at a 0.5 by 0.5 degree resolution. All three scenarios follow the qualitative scenario characteristics, as outlined in the original SRES scenarios. Two scenarios (B1 and B2) also follow (with minor adjustments due to scenario improvements) the original SRES quantifications at the level of 4 and 11 world regions respectively. The quantification of the original SRES A2 scenario has been revised to reflect recent changing perceptions on the demographic outlook of world population growth. In this revised “high population growth” scenario, A2r world population reaches some 12 billion by 2100 (as opposed to some 15 billion in the original SRES A2 scenario) and is characterized by a “delayed fertility transition” that is also mirrored in a delayed (economic) development catch-up, resulting in an initially stagnating and subsequently only very slow reduction in income disparities. The spatially explicit scenario interpretation proceeds via two steps. Through a combination of decomposition and optimization methods, world regional scenario results are first disaggregated to the level of 185 countries. In a subsequent second step, national results are further disaggregated to a grid cell level, taking urbanization and regional (rural–urban) income disparities explicitly into account. A distinguishing feature of the spatially explicit scenario results reported here is that both methodologies, as well as numerical assumptions underlying the “downscaling” exercise, are scenario-dependent, leading to distinctly different spatial patterns of population and economic activities across the three scenarios examined.     

Efficient markets and Bayes’ rule

Summary. A series of financial anomalies motivated the development of new theories that modify the rational expectations ideal. Two possibilities have been systematically explored. The literature on behavioral finance relaxes the assumption that agents form beliefs according to the laws of probability and assume, instead, that simpler heuristic rules are used. Another stream of the literature assumes that agents process information according to Bayes rule, but do not posses sufficient information to know the true data generating process. In this paper, Bayesian and Behavioral agents coexist and trade in a standard dynamic asset pricing model. A long-standing conjecture is demonstrated. It is shown that, under suitable assumptions, Bayesian agents drive Behavioral, non-Bayesian agents out of the market. Hence, asset prices are eventually determined under the Bayesian paradigm.Received: 3 June 2004, Revised: 17 September 2004, JEL Classification Numbers: D83.Preliminary versions have circulated under the titles Markets Favor Bayesian Models and Market Selection of Empirical Models under Limited Information. I thank Larry Blume, David Easley, Larry Epstein, Armando Gomes, Bruce Hansen, Lars Hansen, Richard Kihlstrom, Grace Koo, George Mailath, Werner Ploberger, Andrew Postlewaite and Shakeeb Khan for useful comments. I also thank participants at the NBER GE meetings, Evolutionary Finance conference in Zurich, Latin American Meetings of the Econometric Society, Stanford Institute for Theoretical Economics, the Instituto de Matematica Pura e Aplicada, the theory seminar at Brown, Chicago, Harvard-MIT, Minnesota, Penn and Wisconsin. I gratefully acknowledge the financial support from the National Science Foundation Grant SES 0109650.     

Bargaining Outcomes with Double-Offer Arbitration

Increasingly, arbitration is becoming used to resolve bargaining disputes in a variety of settings. Reducing dispute rates is often listed as a main goal in designing arbitration mechanisms. Conventional arbitration and final-offer arbitration are two commonly used procedures, but theoretical examinations of these arbitration procedures show that disputants’ final bargaining positions do not converge and disagreement is likely. This article contains results from a set of experiments designed to compare bargaining outcomes under the two commonly used arbitration procedures with outcomes under an innovative procedure called “double-offer” arbitration (Zeng et al., 1996). This procedure requires that disputants make two final offers at impasse: a primary and a secondary offer. The arbitrator evaluates the pairs of offers using a linear criterion function, and theory suggests the secondary offers converge to the median of the arbitrator’s preferred settlement distribution. Because the procedure’s rules are that convergence of offers generates a settlement at those offers, this theoretical convergence result implies that arbitration is not needed in the end. Experimental results indicate that dispute rates in double-offer arbitration are, on average, about the same as dispute rates in conventional arbitration. However, other results show reason to favor double-offer arbitration. Specifically, in repeated bargaining, there is concern over whether use of an arbitration procedure becomes addictive and makes bargainers more likely to use the procedure in the future-a “narcotic effect.” The data show that double-offer arbitration is non-addictive, whereas both conventional and final-offer arbitration are.     

Capital markets integration, growth and income distribution

The paper considers a two-country model of overlapping generation heterogenous economies with intergenerational transfers carried out in the form of bequest and investment in human capital. We examine in competitive equilibrium the transitory and long-run effects of capital markets integration. First, we explore how the regime of public education affects the dynamics of the integrated economy. Second, we study the effects of capital markets integration, in equilibrium, on the intragenerational income distribution in both the host and investing country.     

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.     

An Eclectic Approach to Estimating U.S. Potential GDP

Rennison (Comparing alternative output gap estimations: a Monte Carlo approach, 2003) has provided simulation-based evidence showing that the joint use of extended multivariate filters and structural vector autoregression models is optimal for estimating potential output. We use this approach to estimate the two components of potential GDP: the full-employment labour input and trend labour productivity. This decomposition is useful for identifying sources of fluctuations in potential output. It reveals, for example, that the vigorous growth rate of U.S. potential GDP recorded during the second half of the 1990s is attributable to a fall in the structural rate of unemployment and a marked upswing in trend productivity growth.     

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.     

云南GDP的灰色预测和分析

文章通过建立灰色系统理论建立预测模型,结合云南省过去几年的GDP的数值,预测未来几年云南省GDP的发展状况,为政府管理部门,以及其他经济部门的决策提供科学依据,并对预测结果进行评价。