Assessing Global Computable General Equilibrium Model Validity Using Agricultural Price Volatility

Computable General Equilibrium (CGE) models are commonly used for global agricultural market analysis. Concerns are sometimes raised, however, about the quality of their output since key parameters may not be econometrically estimated and little emphasis is generally given to model assessment. This article addresses the latter issue by developing an approach to validating CGE models based on the ability to reproduce observed price volatility in agricultural markets. We show how patterns in the deviations between model predictions and validation criteria can be used to identify the weak points of a model and guide development of improved specifications with firmer empirical foundations.     

Market Growth, Structural Change, and the Gains from the Uruguay Round

It is found that market growth and structural changes will affect the results of quantitative analyses of the Uruguay Round. Rapid economic growth in Asia, and relatively deeper cuts in protection in that region, result in larger proportionate welfare gains in the year 2005 than in the year 1992. It is also found that changing comparative advantage, and shifts in global demand, result in substantial changes in the restrictive effects of the bilateral quotas on textiles and apparel. Accounting for the factors associated with market growth and structural change adds 30% to the estimates of global welfare gains from the Uruguay Round.     

Procompetitive Effects of Foreign Competition on Domestic Markups

A short-run model for estimating the procompetitive effects of foreign competition on markups in an oligopolistic, domestic industry is developed and estimated using data on the Australian automobile industry. Estimates reveal that these effects are rather large and cannot be ignored when predicting the effects of a shock affecting foreign costs. These estimates can also facilitate inferences about the nature of interfirm rivalry.     

Land Use in the 21st Century: Contributing to the Global Public Good

This paper focuses on the evolution of global public goods related to the world's land resources over the course of the 21st century, their potential impacts on the world's poorest households, as well as prospects for policy interventions aimed at enhancing these outcomes. It begins with global scale projections to 2100 of land use and associated goods and services, including food, fuel, timber, greenhouse gas emissions, carbon sequestration and biodiversity. This is followed by in‐depth discussion of each of these services and the challenges of providing these public goods in sufficient quantities to advance societal welfare—especially that of the world's poorest households. The paper concludes with a discussion of policies aimed at promoting the provision of land‐based public goods and how they could be altered to be more pro‐poor. Within this context, the paper argues that access to geospatial analysis tools and information on climate, land use and tenure, poverty and environmental indicators will become increasingly valuable to both public and private decision makers.     

Impacts of trade reform: sensitivity of model results to key assumptions

The WTO’s Doha Development Agenda has generated demand for estimates of the potential economic consequences of global trade reform. Recent improvements in the GTAP dataset have provided a much better representation of tariff restrictions as of 2001. However, despite its use by most global trade modelers, substantial differences in results emerge from different computable general equilibrium exercises. To help understand these differences, this paper examines the sensitivity of full global and regional trade liberalization results from the GTAP model, using the GTAP version 6.1 database, to different assumptions about factor mobility, fiscal neutrality, macro-economic closure, and trade (Armington) elasticities.

Why Isn't the Doha Development Agenda more Poverty Friendly?

Critics of the Doha Development Agenda rightly point to the lack of aggressive reform in wealthy countries for its role in dampening developing country gains. The authors find that the absence of tariff cuts on staple food products in developing countries also critically limits poverty reduction in those countries. Based on their analysis of the impacts of multilateral trade policy reforms in a sample of 15 developing countries, they find there is some evidence of poverty increases amongst the poor who work in agriculture when they lose protection for their earnings. However, these effects are minimized when agricultural tariffs are cut in all developing countries, and when the impact of lower food prices on low income consumers is taken into account in their 15 country sample.     

PSEs and the Mix of Measures to Support Farm Incomes

In summary, the mix of support provided to agriculture does matter when PSEs are to be cut. Across-the-board reductions in individual components of PSEs will have different implications for output, exports, land values and employment in different countries. These differences can be systematically related to the type of instruments used to support agriculture. For example, cutting subsidies on an input such as fertilizer can result in greater long-run reductions in output, exports and employment in agriculture than would cuts in output subsidies (of equal magnitude). These differences may make it attractive for countries engaging in partial liberalization to change the mix of subsidies, even as they reduce their aggregate PSE. In so doing, they may be able to lessen, or even eliminate, some of the deleterious effects of reduced farm support. For example, the United States could maintain the demand for farm labour, while cutting its aggregate PSE in half, by shifting the mix of farm support towards selected input subsidies. By contrast, there appears to be little incentive for substituting export subsidies for output subsidies under the ‘pure’ PSE approach proposed by Professor Tangermann et al. This is because such a switch would have to be accompanied by further reductions in budgetary outlays in order to avoid exceeding the PSE target agreed in negotiations.     

Bridging the Gap between Partial and Total Factor Productivity Measures Using Directional Distance Functions

Technical dependencies as well as data constraints limit our ability to allocate inputs across sectors and hence our ability to measure sectoral productivity. We adapt a directional measure of efficiency to the measurement of sector-specific productivity that does not require allocating all inputs across sectors. Applied to the agricultural sector of a group of countries, the results show important differences in livestock and crops productivity growth. Commonly used partial factor productivity measures for livestock and crops tend to overestimate productivity growth in most developing countries while underestimating it in European countries.     

Predicting within country household food expenditure variation using international cross-section estimates

International cross-section demand systems have not been tested on their ability to accurately predict within country consumption expenditures. This paper reports on such a validation exercise for the case of food budget share predictions across expenditure percentiles within Bangladesh.     

FACTOR MARKET INCIDENCE OF AGRICULTURAL TRADE LIBERALIZATION: SOME ADDITIONAL RESULTS

Liberalization of trade implies changes in producer prices, which has consequences for farm income, agricultural employment and asset values. The relative incidence of the effect of changes in prices on fixed factors depends on the rclative magnitude of the Morishima elasticities of substitution in agricultural production.