但是系统自动omit了Current组,导致无法画出Current点。
查阅了论坛内外的帖子,有的并未提到有omitted问题,有的说stata会自动omit最后一项(但在我这里omit了中间的Current)。想请教各位大神:如何保留Current?或是,在coefplot中如何指定omitted项?
- gen Dyear = year - 2007
- gen Before2 = (Dyear==-2&HIGI==1)
- gen Before1 = (Dyear==-1&HIGI==1)
- gen Current = (Dyear==0&HIGI==1)
- gen After1 = (Dyear==1&HIGI==1)
- gen After2 = (Dyear==2&HIGI==1)
- gen After3 = (Dyear==3&HIGI==1)
- gen After4= (Dyear==4&HIGI==1)
- global time "Before2 Before1 Current After1 After2 After3 After4"
- reghdfe L1PAT HIGI $time $control ,absorb(i.industry i.year)
- est store m1
- coefplot m1,keep($time) vertical ///
- addplot(line @b @at) yline(0)