On the basis of the BP test, we reject the null hypothesis that time FEs are not important determinants of canola and wheat yields—we have statistically significant evidence that time FEs are jointly significant determinants of canola yields and should be included in the regression model. [...] The addition of variables accounting for precipitation between May and August account for an additional 4.4% of variation in yields and slightly reduce SZ estimates to 23.4% and 16.1% for black and dark brown SZs, respectively. [...] Proceedings of the National Academy of Sciences of the United States of America. [...] Proceedings of the National Academy of Sciences of the United States of America. [...] Proceedings of the National Academy of Sciences of the United States of America.
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- Pages
- 33
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- Canada
