Mensuração das Elasticidades-preço da Demanda, Cruzada e Renda no Mercado de Etanol Brasileiro: um estudo usando painéis cointegrados

The future shortage of fossil energy is not shared by the entire academy, but the need of renewable energy sources is a consensus. Based on this, the ethanol from sugarcane in Brazil becomes an excellent energy alternative by offering better indicators, such as: less land intensity, lower production costs and larger CO2 reduction when compared with other energy producing crops. However, there are no studies that estimate the long run ethanol demand using panel data or either estimate it at regional level. Therefore, this study aims to estimate the price, income and cross price demand elasticities for ethanol in the short and long run. The estimates are both at national and regional levels for Brazil, from July 2001 to July 2011, on a monthly basis. Panel data econometrics are used and forecasts use the following estimators: General Least Squares (GLS) with correction for heteroscedasticity for short run and Dynamic Ordinary Least Squares (DOLS) for long run. Results indicate that ethanol is price elastic, with elasticity around -1.42 and -3.30 for the short and long run, respectively. There was an increase of cross and price elasticities in the short run in the post-flex period.

学界尚未就化石能源未来短缺的观点达成普遍共识，但可再生能源的发展必要性已成为学界共识。基于此，巴西甘蔗乙醇相较于其他能源作物，凭借更低的土地占用强度、更低的生产成本以及更高的二氧化碳减排量，成为了极具竞争力的能源替代方案。然而，目前尚无研究利用面板数据估算乙醇的长期需求，亦未在区域层面开展相关需求估算工作。有鉴于此，本研究旨在估算乙醇在短期与长期内的价格、收入及交叉价格需求弹性。本次估算覆盖巴西全国与区域两个层面，样本区间为2001年7月至2011年7月的月度数据。本研究采用面板数据计量经济学方法，所用估计器包括：用于短期分析的异方差（heteroscedasticity）修正广义最小二乘法（General Least Squares, GLS），以及用于长期分析的动态普通最小二乘法（Dynamic Ordinary Least Squares, DOLS）。研究结果显示，乙醇需求具有价格弹性：短期弹性约为-1.42，长期弹性约为-3.30。在价格浮动政策实施后的阶段，短期交叉价格弹性与自身价格弹性均有所上升。