Modelo de Análise da Oferta de Exportação de Milho Brasileira: 2001 a 2012

Abstract: This study aims to estimate the corn export supply function for Brazil from 2001 to 2012. For this analysis we developed a theoretical model estimated using the cointegration and vector error correction model (VEC). The variables used were: corn exports, international corn price, poultry slaughters, soybean prices and world GDP. The results obtained showed the existence of long-term relationship between the variables. The international corn price, poultry slaughters, soybean prices and world GDP had a significant impact on corn exports, showing signs as expected by the theoretical model. There was a positive impact on corn exports after an unanticipated shock in the soybean price and negative impact after a not anticipated shock the slaughter of poultry. In relation to the international price, it was found that a shock in this variable has a negative impact on corn exports. In order to assess the relationships between the domestic price and the international price of corn, there was the weak exogeneity test between the variables and it was found that, despite this market still does not have the Law of One Price, changes in the international corn price affect the domestic price.

摘要：本研究旨在估算2001至2012年巴西玉米出口供给函数。本次分析中，我们构建了理论模型，并采用协整（cointegration）分析与向量误差修正模型（Vector Error Correction Model, VEC）开展估计。研究所采用的变量包括：玉米出口量、国际玉米价格、家禽屠宰量、大豆价格以及世界国内生产总值（GDP）。研究结果显示，各变量间存在长期均衡关系。国际玉米价格、家禽屠宰量、大豆价格与世界GDP均对玉米出口产生显著影响，且影响方向符合理论模型的预期。大豆价格遭遇未预期冲击后，玉米出口将受到正向影响；而家禽屠宰量遭遇未预期冲击后，玉米出口则受到负向影响。针对国际玉米价格变量，研究发现其遭遇冲击后会对玉米出口产生负向影响。为评估玉米国内价格与国际价格间的关联，我们对两变量开展了弱外生性检验（weak exogeneity test），结果显示：尽管该市场尚未满足一价定律（Law of One Price），但国际玉米价格的变动会对国内价格产生影响。