问题如下：
3. Regarding Question 3, the Pres party dummy variable in the model indicates that the mean monthly value for the excess stock market return is:
选项：
A.1.43 percent larger during Democratic presidencies than Republican presidencies.
B.3.17 percent larger during Democratic presidencies than Republican presidencies.
C.3.17 percent larger during Republican presidencies than Democratic presidencies.
解释：
B is correct.
The coefficient for the Pres party dummy variable (3.17) represents the increment in the mean value of the dependent variable related to the Democratic Party holding the presidency. In this case, the excess stock market return is 3.17 percent greater in Democratic presidencies than in Republican presidencies.
题目中好像写了是0.01表示1%，那3.17应该是317%？
