Note, you need to put this data into Gretl. Suppose there is a new student tax where every Ivy League University student would need to pay a fat 1000 dollar tax to attend. Suppose we have data on the following universities in the year before the tax and the year when the tax was implemented. School Ivy Enrollment1 Enrollment2 OSU 0 12,450 11,125 MIT 1 27,500 21,680 Harvard 1 3,208 2,102 Stanford 1 4,512 1,003 Yale 1 88,100 52,000 Kent State 0 16,230 14,212 Here the 1 indicates it is from before the tax and the 2 means after the tax. Ivy is a dummy variable for if the school is an Ivy League University. Using the difference in difference estimator estimate the impact of the tax on enrollment. (See the 2/25 lecture if you need a hint)