英文文献：Effects of Economic Growth, Trade Openness, Deforestation and Agricultural Trade on African Environmental Quality (1960-2008): A 2SLS Approach-经济增长、贸易开放、森林砍伐和农业贸易对非洲环境质量的影响(1960-2008年):2SLS方法
英文文献作者：Onoja, Anthony O.,Achike, A.I.
英文文献摘要：
This study ascertained the effects of agricultural commercialization (agricultural net exports), deforestation as represented by exports of forestry products, economic growth and trade liberalization on the level of green house gas (CO2) emissions in Africa. It relied on World Bank data (economic development indicators) between 1960 and 2008. Two Stage Least Squares (2SLS) regression model (using logged variables) was applied in the study. Standard econometric diagnoses such as specification test, heteroscdasticity, autocorrelation and endogeneity tests were performed and their results validated the model’s use. All variables in the main equation were statistically significant and conformed to theoretical expectations. It was confirmed from our hypotheses tests that agricultural commercialization (p<0.03), forestry trade or deforestation (p<0.01), trade openness (p<0.01) as well as economic growth (p<0.01) all exerted significant influences on the level of CO2 emissions in Africa over the period in review. Surprisingly, urbanization, contrary to earlier researchers’ findings indicated a positive and significant influence on CO2 emission. Hence we recommended that Africa should begin to integrate policies that will reduce pollution especially (CO2 emission) in her drive for agricultural and economic growth. Environmentally efficient technologies that will build up less CO2 in African environment should be developed and adopted by farmers across the continent as they target the export markets; while regional efforts should be made to regulate trade and investment with the aim of reducing the adverse effects of trade activities such as deforestation and pollution of the environment.

这项研究确定了农业商业化(农业净出口)、森林砍伐(以林业产品出口为代表)、经济增长和贸易自由化对非洲温室气体(CO2)排放水平的影响。它依赖于世界银行1960年至2008年的数据(经济发展指标)。本研究采用两阶段最小二乘(2SLS)回归模型(使用记录变量)。对模型进行了规范检验、异方差检验、自相关检验和内生性检验等标准计量诊断，其结果验证了模型的有效性。主方程中的所有变量均具有统计学意义，符合理论预期。从我们的假设检验中证实，农业商业化(p<0.03)、林业贸易或森林砍伐(p<0.01)、贸易开放(p<0.01)以及经济增长(p<0.01)都对审查期间的非洲CO2排放水平产生显著影响。令人惊讶的是，与早期研究人员的发现相反，城市化对二氧化碳排放有着积极而显著的影响。因此，我们建议非洲应该开始将减少污染特别是减少二氧化碳排放的政策纳入其推动农业和经济增长的行动中。非洲大陆各地的农民应该开发和采用将在非洲环境中减少二氧化碳排放的环保技术，因为他们的目标是出口市场;同时，应作出区域努力来管制贸易和投资，以期减少诸如砍伐森林和环境污染等贸易活动的不利影响。