个人感觉用R比较好

stata比sas简单啊

那之后的反事实分解法也可以用R解决嘛？

stata程序是挺简单的，就是不知道后面的反事实分解法怎么做？

Any software should be fine. If I were you I would do it different.

For example, SAS has QUANTREG Procedure which will do the job. The QUANTREG can be viewed as a linear programming problem and solve by linear programming. If you are familiar with linear programming, then you can write it by yourself. After you compare the results from  QUANTREG and your program, you will have better understand the QUANTREG. Then you will be comfortable to use the QUANTREG.