ECONOMIC MODELING AND THE FALSE TRADEOFF BETWEEN ENVIRONMENTAL PROTECTION AND ECONOMIC GROWTH

One important element of the current policy debate on what measures should be taken to reduce greenhouse gas emissions is the controversy over the costs of reducing those emissions. "Top-down" macroeconomic and general equilibrium models give much higher estimates of the costs than "bottom-up" models based on microeconomic and engineering data. This paper investigates the causes of the divergence between the two modeling approaches. The conventional top-down models incorporate strong implicit assumptions about maximization, technical progress, and organizational efficiency that predetermine their results. However, these assumptions are questionable on both theoretical and empirical grounds. Economic assessment of policy alternatives would benefit. from analyses that take account of the actual characteristics of business firms and other organizations that emit greenhouse gases in the course of their activities.     

NASH BARGAINING AND CO-OPERATIVES

This paper develops the generalised Nash bargaining solution for a bargaining co-operative selling its output to a single buyer. Three assumptions for co-operative members' behaviour are examined: profit maximisation, co-operative surplus maximisation and maximising members' price. Solutions are compared and comparative statics presented for these alternative assumptions and the bargaining over price and quantity transacted. The most striking feature of the results is that pursuing the objective of maximising members' price does not necessarily lead to the highest members' price     

INTERNATIONAL TRADE AND COURNOT EQUILIBRIUM: EXISTENCE,UNIQUENESS AND COMPARATIVE STATICS *

This paper proves the existence and uniqueness of Cournot equilibrium in models of international trade under oligopoly. The existence of Cournot equilibrium is established without the usual assumption that profit functions are concave. Instead the proof uses a weaker‘aggregate concavity’condition. A simple proof is used to establish the uniqueness of the equilibrium. And, the paper considers the implications of the assumptions, used to prove the existence and uniqueness of the equilibrium, on the comparative static results.     

DUAL ECONOMY MODELS: RETROSPECT AND PROSPECT

The paper surveys recent work on dual economy models starting from the famous 1961 Jorgenson paper and ending with some of the new contributions to the literature on North-South trade which have the same analytical structure as the dual economy model. Various models are compared with respect to assumptions about asymmetries, speeds of adjustment and factor immobilities. Two important conclusions are noted: dynamic behaviour is often quite sensitive to the ranking of adjustment speeds and the direction of further research should be toward further disaggregation.     

FINANCIAL MARKET IMPERFECTIONS AND IRREGULAR GROWTH CYCLES

In this paper we analyze the generation of endogenous growth and irregular fluctuations in a simple New Keynesian model whose background assumptions are borrowed from a class of asymmetric information models popularized by Greenwald and Stiglitz. We extend the framework put forward by Greenwald and stiglitz taking explicitly into account technological progress as the engine of growth. We show how irregular endogenous fluctuations can arise around an endogenous trend: the traditional view of fluctuations as 'short run' phenomena must be abandoned in favour of models of fluctuating growth.     

Intertemporal consumption with directly measured welfare functions and subjective expectations

Euler equation estimation of intertemporal consumption models requires many, often unverifiable assumptions. These include assumptions on expectations and preferences. We aim at reducing some of these requirements by using direct subjective information on respondents’ preferences and expectations. The results suggest that individually measured welfare functions and expectations have predictive power for the variation in consumption across households. Furthermore, estimates of the intertemporal elasticity of substitution based on the estimated welfare functions are plausible and of a similar order of magnitude as other estimates found in the literature. The model favored by the data only requires cross-section data for estimation.     

Sensitivity analysis of efficiency rankings to distributional assumptions: applications to Japanese water utilities

This article examines the robustness of efficiency score rankings across four distributional assumptions for trans-log stochastic production-frontier models, using data from 1221 Japanese water utilities (for 2004 and 2005). One-sided error terms considered include the half-normal, truncated normal, exponential and gamma distributions. Results are compared for homoscedastic and doubly heteroscedastic models, where we also introduce a doubly heteroscedastic variable mean model, and examine the sensitivity of the nested models to a stronger heteroscedasticity correction for the one-sided error component. The results support three conclusions regarding the sensitivity of efficiency rankings to distributional assumptions. When four standard distributional assumptions are applied to a homoscedastic stochastic frontier model, the efficiency rankings are quite consistent. When those assumptions are applied to a doubly heteroscedastic stochastic frontier model, the efficiency rankings are consistent when proper and sufficient arguments for the variance functions are included in the model. When a more general model, like a variable mean model is estimated, efficiency rankings are quite sensitive to heteroscedasticity correction schemes.     

TAXES AND INCOME: A MICROUNIT ANALYSIS

The paper details the methodology used and the results obtained in a recently completed study of the total U.S. tax burden based on microdata survey files. The method of constructing the data base—the 1966 MERGE file—is discussed, and the needed imputations and adjustments to income and taxes to bring the file totals up to national income aggregates are described. An explanation is included of adjusted family income, a unique income concept used in the study to measure and compare tax burdens.
The study involved the evaluation of errective tax burdens under eight different assumptions regarding the incidence of the various major taxes. Those assumptions are detailed and the results of the study are presented. The essential conclusion of the study is that the overall impact of the tax system is virtually proportional for 90 percent of the families in the United States regardless of the incidence assumptions used. However, substantial differences in tax burdens were found among various subgroups of the population.     

Financial crises as herds: overturning the critiques

Financial crises are widely argued to be due to herd behavior. Yet recently developed models of herd behavior have been subjected to two critiques which seem to make them inapplicable to financial crises. Herds disappear from these models if two of their unappealing assumptions are modified: if their zero-one investment decisions are made continuous and if their investors are allowed to trade assets with market-determined prices. However, both critiques are overturned—herds reappear in these models—once another of their unappealing assumptions is modified: if, instead of moving in a prespecified order, investors can move whenever they choose.     

POLLUTION AND POLLUTION ABATEMENT IN THE NATIONAL ACCOUNTS

Building on the approach of Weitzman, as extended by Hartwick and Mäler, five models of national accounts in a dynamic competitive economy with pollution externalities are constructed: flow pollutants, stock pollutants, fossil fuels and CO₂, living resources and acid rain, and household defensive expenditures. The results measure welfare rather than national product per se . The general conclusions are that abatement expenditures should be treated as intermediate consumption, that adjustments need to be made for both pollution emissions and natural pollution dissipation processes, that marginal social costs should be used to value emissions, and that the level of environmental services must be valued in measuring welfare. Not only should household defensive expenditures not be subtracted from the welfare measure, under plausible assumptions the adjustment to welfare (as opposed to NNP) includes a value greater than the level of household defensive expenditure.     

METHODS OF ESTIMATING HOUSEHOLD EQUIVALENCE SCALES: AN EMPIRICAL INVESTIGATION

This paper presents empirical evidence regarding key assumptions of the Rothbarth and Barten methods of constructing household equivalence scales. The assumption of separability in the Rothbarth model is investigated by examining the implied intra-household allocation of specific goods and by examining studies of economies of scale in household consumption. The assumption of the exogeneity of the distribution parameters in the Barten model is related to the results of empirical studies of clothing expenditures. This paper suggests that empirical evidence fails to support the assumptions maintained in these theoretically sophisticated models of household income equivalence.     

Homogeneity masquerading as variety: the case of horizontal innovation models

The literature on ‘horizontal innovation’ claimsto analyse cases where unbounded endogenous growth comes froman increasing variety of intermediate goods. The present papercontends that a good sample of representative models in thisliterature share two essential assumptions regarding productiontechnology, and that these assumptions together amount to assumingthe homogeneity of various intermediate goods. In these models,there is no variety of intermediate goods to increase owingto R&D activities; what increases is a mass of a singlehomogeneous intermediate good.     

Beyond Behavioral Finance

Throughout its history, finance theory has made certain simplifying assumptions regarding human behavior and concerned itself with whether the implications of these assumptions were true and not with whether the assumptions themselves were. Recently, however, more interest has been shown in experimental investigation of these assumptions, and the resultant behavioral finance has been presented as a significant departure from the current research paradigm. Recent research in cognitive science, however, is finding that the mind can and does work differently than traditional finance assumes, and the differences between the behavioral assumptions of traditional finance and the supposedly more realistic ones of today's behavioral finance are frequently superficial. Knowledge and knowing are likely to be profoundly different from the forms in which we have incorporated them in our extant models, both traditional and behavioral, and they differ in ways similar to those which, for example, have differentiated corporations from corporate images in marketing. To truly understand what is going on we must go beyond behavioral finance to address these differences.     

对经济学模型化的批判:结论隐藏在基本前提假设中——从一个效用函数导致不同的结果分析经济学模型化中的问题

本文通过戴维·罗默《高级宏观经济学》教科书的一个效用函数在三个经典模型--无限期界拉姆齐模型、戴蒙德世代交叠模型和真实经济周期模型中导致的不同结果,发现结果不同的关键原因在于基本前提假设的微小差异。说明经济学模型化的实质--结论隐藏在基本前提假设中。换句话说,数学推导是走过场,是一种精致的包装。前提假设决定结论。     

Do Three Trade Blocs Minimize World Welfare?

Two interesting results have emerged from research on symmetric models that make the analysis of bilateralism tractable. Krugman reported that three trade blocs minimize world welfare. Frankel, Stein, and Wei argued that the formation of continental trading blocs can reduce welfare. This paper shows that these results are not robust. In particular, it is argued that the inclusion of more realistic assumptions into a symmetric model changes the picture considerably. Specifically, if one allows for transportation costs, conventional results are obtained. The phenomenon of three welfare-minimizing blocs and "super-natural" blocs disappears.     

The measurement of income and price elasticities

In a complete system of disaggregated demand equations, the econometrician must limit himself to the measurement of a small number of parameters for each commodity. Since interest often focuses on the income and own-price elasticities for each good, it is natural to look for models which allow independent measurement of these while providing plausible assumptions about the less essential responses. This paper surveys a number of common theoretical specifications which purport to do this, and argues that these are unsatisfactory. The conclusions are supported by an empirical comparison on British data of the results of three models, one of which is new and is designed to remedy some of the deficiencies of standard practice.     

Exploring the market for breakthrough technologies

In this article, the gap between futures research (long term) and market research (short term) is closed in two ways. Firstly, by describing methods of market exploration that can be used earlier on in the process of development and diffusion of breakthrough technologies, so market research can be applied along with futures research. Secondly, the gap is closed by actually combining futures research and market research. We start the article from the perspective of the market research discipline and describe the problems in market research that require new approaches. The validity of market research results is often low when breakthrough technologies enter the market. To investigate this problem, assumptions for valid market research results are presented. In some cases, when breakthrough technologies first enter the market, these assumptions do not hold and market research becomes problematic whereas in other cases customers' needs and preferences are not an issue at all and attention focuses on technological issues. Potential solutions to explore the market in the former cases are suggested. Four approaches are distinguished: (1) adapting existing methods; (2) combining consumer research with market structure analysis or futures research; (3) using theoretic models; and (4) probe and learn approaches. These approaches require different subsets of assumptions and are therefore applicable in different situations.     

GENERAL AND PARTIAL EQUILIBRIUM THEORY IN BORK'S ANTITRUST ANALYSIS

In applying economic theory to evaluate antitrust laws, Judge Robert Bork explicitly favors a partial equilibrium over a general equilibrium approach. He believes the general model assumes away too many real-world aspects to be usefully employed as a criterion by which to judge real-world laws.
However, Bork's partial equilibrium replacement, the Oliver Williamson trade-off model, implicitly contains many of the same assumptions as general equilibrium theory. Equilibrium prices in all industries, an absence of external effects, and well-defined demand curves are assumptions of both general equilibrium theory and the Williamson trade-off model. If one theory is judged inadequate because of these assumptions, so should the other.
Bork's analysis is more consistent with market process theory than with his own partial equilibrium approach. Market process theory assumes neither the absence of externalities, nor the presence of well-defined demand and equilibrium prices in all industries.     

HETEROGENEITY AND REDISTRIBUTION: BY MONETARY OR FISCAL MEANS?*

In models with heterogeneous agents, issues of distribution and redistribution jump to the fore, raising the question: Which policies—monetary or fiscal—work most effectively in transferring income between groups? From Townsend's turnpike model, two basic results emerge to help answer this question. First, the zero lower bound on nominal interest rates often appears as an obstacle to redistribution by monetary means. Second, assumptions about the government's ability to raise tax revenue without distortion and to discriminate between agents in distributing that tax revenue play a large role in determining whether agents prefer to redistribute income by fiscal means instead.     

The Interpretation of Instrumental Variables Estimators in Simultaneous Equations Models with an Application to the Demand for Fish

In markets where prices are determined by the intersection of supply and demand curves, standard identification results require the presence of instruments that shift one curve but not the other. These results are typically presented in the context of linear models with fixed coefficients and additive residuals. The first contribution of this paper is an investigation of the consequences of relaxing both the linearity and the additivity assumption for the interpretation of linear instrumental variables estimators. Without these assumptions, the standard linear instrumental variables estimator identifies a weighted average of the derivative of the behavioural relationship of interest. A second contribution is the formulation of critical identifying assumptions in terms of demand and supply at different prices and instruments, rather than in terms of functional-form specific residuals. Our approach to the simultaneous equations problem and the average-derivative interpretation of instrumental variables estimates is illustrated by estimating the demand for fresh whiting at the Fulton fish market. Strong and credible instruments for identification of this demand function are available in the form of weather conditions at sea.