Xtreg stands for panel data regression, and the prefix xt can be said to be the symbol of panel data command, which is different from OLS regression command reg.

In this example, the explanatory variable is exit 1, the last four variables are all explanatory variables, fe stands for fixedeffect, and R stands for robust, that is, the cluster robust standard deviation is used. For panel data estimation, R is automatically clustered to the cross-sectional dimension. If you want to change the clustering level, you can manually change r to cluster(hy), and the level to be clustered is in brackets, such as hy (industry).

Regarding R-sq, that is, RSquare, we should also emphasize it here. It can be found that the regression results show three R-AQs, which one should be used? As mentioned earlier, there are three methods to estimate the fixation effect. Stata defaults to Withinestimate, so you should use the first of the three r-sqs: within=0.02.

However, there is also a "smart" identification method, that is, the regression result is directly exported to word through the command, and then it depends on which R-sq is given by the software (the command to export the regression result has been mentioned earlier, such as Outleg 2 and esttab can be well implemented).