Data issues in general equilibrium modelling

In recent years global general equilibrium (GE) models have been used to analyse policy issues such as trade liberalisation, regional integration and environmental policies. While a global CGE model is an excellent tool to perform a comprehensive analysis of such policies, it requires an enormous amount of data to calibrate or parameterise the model itself. Quality differences in the data sets might affect the results of the model simulation. Identifying and removing problems in the database is an important task for the effective use of a CGE model. In this paper, we suggest an approach to detect and remove major inconsistencies from the database of a CGE model. To illustrate, we examine and modify selected interindustry transactions in the GTAP version 5 database, a general equilibrium database of the global economy. The revised database was evaluated against the original by undertaking technical change and trade liberalisation experiments using Global Trade Analysis Project (GTAP) model. Results show that estimates using the modified database are more credible than those from the original database.International Relations/Trade, Research Methods/ Statistical Methods,

CHIMP: A SIMPLE POPULATION MODEL FOR USE IN INTEGRATED ASSESSMENT OF GLOBAL ENVIRONMENTAL CHANGE

We present the Canberra-Hamburg Integrated Model for Population (CHIMP), a new global population model for long-term projections. Distinguishing features of this model, compared to other model for secular population projections, are that (a) mortality, fertility, and migration are partly driven by per capita income; (b) large parts of the model have been estimated rather than calibrated; and (c) the model is in the public domain. Scenario experiments show similarities but also differences with other models. Similarities include rapid aging of the population and an eventual reversal of global population growth. The main difference is that CHIMP projects substantially higher populations, particularly in Africa, primarily because our data indicate a slower fertility decline than assumed elsewhere. Model runs show a strong interaction between population growth and economic growth, and a weak feedback of climate change on population growth.population model, long term projections, global change, integrated assessment

O conceito de consumidor direto e a jurisprudência do Superior Tribunal de Justiça

- Texto de autoria de Ministra do Superior Tribunal de Justiça.Trata, sob o enfoque jurídico e econômico, o conceito de consumidor direto, contextualizando-o, de um lado, com as duas escolas de pensamento formuladas sobre o tema, e, de outro, com os recentes avanços jurisprudenciais desenvolvidos pelo Superior Tribunal de Justiça (STJ). Comenta que a Escola Subjetiva considera que a aquisição ou uso de bem ou serviço para o exercício de atividade econômica, civil ou empresária (CC/02, art. 966, caput e parágrafo único), descaracteriza requisito essencial à formação da relação de consumo, qual seja, ser o consumidor o destinatário final da fruição do bem. Informa que a linha de precedentes adotada pela Quarta e Sexta Turmas deste STJ coaduna-se com os pressupostos da teoria subjetiva ou finalista, restringindo a exegese do art. 2º do CDC ao destinatário final fático e também econômico do bem ou serviço. Apresenta ainda a teoria da Escola Objetiva que considera que a aquisição ou uso de bem ou serviço na condição de destinatário final fático caracteriza a relação de consumo, por força do elemento objetivo, qual seja, o ato de consumo. Informa também que a linha de precedentes adotada pela Primeira e Terceira Turmas deste STJ coaduna-se com os pressupostos da teoria objetiva (ou maximalista), considerando-se consumidor o destinatário final fático do bem ou serviço, ainda que venha a utilizá-lo no exercício de profissão ou de empresa. Indica a tendência jurisprudencial do STJ de prevalência da Escola Objetiva. Apresenta precedente recente (Conflito de Competência nº. 41056/SP, julgado em 23/06/2004), em que a Segunda Seção do STJ acolheu, por maioria, o conceito de consumidor direto eleito pela escola objetiva

An analytical framework for incorporating land use change and forestry in a dynamic CGE model

Forestry poses a challenge to computable general equilibrium (CGE) modellers working with recursively dynamic models. This is because of the lag between its inputs and output, which do not correspond to the same time period as other sectors. Inputs are applied for a number of years before a forest is ready for harvest. As a result, attempts in the past to incorporate a well-specified forestry sector in a recursive CGE model have been only partly successful. The purpose of this paper is to fill this gap by presenting a consistent analytical framework which can be used to incorporate forestry into a recursively dynamic global CGE model. A key feature of the framework is that it splits the forestry activity into three parts—planting, holding and harvesting. Planting and harvesting are done by standard production sectors and holding is done by investors, whose behaviour is already modelled in these CGE models. In addition, global forests are classified into three groups—commercial plantation forests, environmental plantation forests and native forests. All harvested forest land is made available for competition for alternative agricultural uses and will be allocated to the activity it is best suited for, given productivity differences for different activities. This framework can be used in a CGE modelling framework to support implementation of the proposed reduced emissions from deforestation and forest degradation (REDD) schemes as well as being applied to study land allocations, nationally and globally, across activities under alternative scenario assumptions. For example, the model can be used to project the effects on food production and prices of an increase in bio-fuel subsidies

Technical Change, Pecuniary Externality and the Market Failure

First, a small open economy is analyzed to show that even a complete and competitive market may fail to produce Pareto-efficient outcomes under conditions of changing technology. It is mainly because price- taking agents can make the prices they face by changing their technology or technique of production. It is then shown that this result holds equally true for the regional sub-economies of this economy. A legal provision of R&D tax/subsidy based on payroll changes is shown to be a second best policy that corrects the market failure with a small dead- weight loss. This policy does not require actual tax collection or subsidy payment and may be used by regional governments to correct technological market failure at regional levels. The provision improves the functioning of the market by eliminating the mismatch between the type of production sector and the type of technological/technical change they introduce.Technical Change, Pecuniary Externality, Market Failure

Endogenous Behaviour of the Tariff Rate in a Political Economy

How would the tariff rate in a political economy respond to changes in exogenous environment? To answer this question a bargain-theoretic approach is adopted and a tariff-endogenous general equilibrium model of a small open political economy is derived. A comparative static analysis of the model shows that the bargained tariff rate changes to compensate, at least in part, for the relative loss of the loser arising from changes in the exogenous environment - be it the domestic factor endowment or the international terms of tradeendogenous-tariff, comparative statics, Nash bargaining games, CGE models, political economy

Data issues in general equilibrium modelling

In recent years global general equilibrium (GE) models have been used to analyse policy issues such as trade liberalisation, regional integration and environmental policies. While a global CGE model is an excellent tool to perform a comprehensive analysis of such policies, it requires an enormous amount of data to calibrate or parameterise the model itself. Quality differences in the data sets might affect the results of the model simulation. Identifying and removing problems in the database is an important task for the effective use of a CGE model. In this paper, we suggest an approach to detect and remove major inconsistencies from the database of a CGE model. To illustrate, we examine and modify selected interindustry transactions in the GTAP version 5 database, a general equilibrium database of the global economy. The revised database was evaluated against the original by undertaking technical change and trade liberalisation experiments using Global Trade Analysis Project (GTAP) model. Results show that estimates using the modified database are more credible than those from the original database