Trade Elasticity, Gravity and Trade Liberalisation: Evidence from the Food Industry
研究了18个食品部门关税取消的贸易效应，发现不同计量方法估算的弹性差异大，贸易自由化会显著增加高收入和新兴国家的食品出口，但发展中国家市场份额普遍下降。
We present an econometric investigation of the trade effect produced by the elimination of tariffs in 18 food sectors for a large sample of developing and developed countries. The standard CES monopolistic competition trade model and the gravity equation were used to estimate trade substitution elasticities, exploring their sensitivity to different estimation methods. Using these elasticities, we simulate the trade effect of the elimination of tariffs, dealing with the problem of uncertainty in the estimated values. Results point to a significant variation in the elasticities estimated by different econometric methods, suggesting that the Poisson pseudo-maximum-likelihood estimator significantly inflates their magnitude. Simulation results indicate that trade liberalisation will strongly increase food exports especially from high income and emerging countries, leading to a general loss of market share by developing countries. The simulated trade flows obtained from the econometric approach are quite close to current evidence based on computable general equilibrium models.