Calibrating spatial models of trade

Empirical spatial models of trade that are based on a mathematical programming specification often exhibit a large discrepancy between the equilibrium solution and the observed demand, supply and levels of trade flows among countries. This discrepancy may be due to several causes. Assuming, however, that a trade model is not misspecified – in the sense that behavior of the economic agents involved in the specific commodity markets has been included in the study and that the relevant policy instruments have been properly taken into account – the cause of discrepancy may be traced either to imprecision of unit transaction costs or to imprecision in the measurement of the demand and supply functions' parameters, or both. Policy assessments based on this type of imprecise models are distorted. This paper presents a methodology for calibrating mathematical programming spatial trade models of increasing complexity, from the one-commodity case to a multi-commodity model with asymmetric slope matrices of demand and supply functions. The proposed calibration procedure identifies corrections of imperfectly measured parameters. The calibrated models generate solutions that exactly reproduce quantities produced and consumed in all countries, as well as trade flows among all pairs of countries, observed in a given base year. Such models may then serve as a springboard for assessing the impact of various policy changes on economic agents in the countries under study.     

Welfare Implications of a Preferential Tariff Reduction for Agricultural Exports from Less Developed Countries vs. a Generalized Tariff Reduction

The paper presents the results of a theoretical study focusing on a comparative evaluation of the welfare effects of a preferential tariff reduction for agricultural exports from less developed countries versus a generalized tariff reduction. The results are derived using a diagrammatic approach. The analysis is developed within a partial equilibrium framework with one commodity, three large countries (importing developed country, exporting developed country, developing country), fixed exchange rates and zero transportation costs. The theoretical model makes provisions for a country to switch from being an exporter to being an importer, or vice versa, as the equilibrium price changes. Three alternative policy scenarios are analyzed: the imposition of a non-discriminatory tariff, a preferential tariff reduction, and a generalized tariff reduction. Two alternative definitions of the welfare functions are used. One is based on consumers' and producers' surplus, the other adds domestic income and changes in foreign exchange earnings/expenditure. Some methodological implications of the specific model used are discussed, along with the impact, in terms of welfare, of the policy scenarios considered.     

EU Economic Partnership Agreements and WTO negotiations. A quantitative assessment of trade preference granting and erosion in the banana market

The paper provides a quantitative assessment of the impact on the banana market of the expansion of trade preferences the European Union granted Africa, Caribbean and Pacific (ACP) countries with the Economic Partnership Agreements (EPA) and of the possible erosion of these preferences as a result of different possible conclusions, if any, of on-going WTO negotiations. The results of the simulations performed suggest that the impact of the EPA on production and consumption of bananas in the EU will be limited, while benefits for ACP countries will be significant (at the expense of Most Favoured Nation (MFN) exporters). An agreement between the EU and MFN countries to end the outstanding WTO disputes on bananas and/or the conclusion of the WTO Doha round may bring an erosion of the preferential margins currently enjoyed by ACP countries of such an order of magnitude as to cancel out most of these benefits.     

The 2005 WTO arbitration and the new EU import regime for bananas: a cut too far?

In 2001 an agreement was reached at the WTO for the EU to introducea ‘tariff-only’ regime which ‘would resultin at least maintaining total market access for MFN banana suppliers’.The analysis shows that, contrary to the WTO 2005 ruling, theimport regime proposed by the EU in the second step of the arbitrationwould have satisfied the requirement. The regime introducedon 1 January 2006 is expected to yield in 2007 MFN imports 400,000 tabove the level that would have occurred under the previousregime. In the longer run, MFN countries will see their exportsexpand, while the opposite would have happened had the new regimenot been introduced.     

The negotiations on agriculture in the Doha Development Agenda Round: current status and future prospects

The paper briefly discusses developments in the negotiationson agriculture in the WTO Doha Development Agenda Round fromJanuary 2000 to September 2005 and identifies the main elementsto be considered when speculating on the outcome of the MinisterialConference in Hong Kong.