create a dummy variable
dum=dummy(boun,subperiod)
* boun = a (2x1) string vector of dates
* subperiod =
- either a string scalar if the dummy is relative to the lone date subperiod
- or a (2 x1) string vector if the dummy is relative to the period subperiod(1) to subperiod(2)
* dum = a ts equal to 1 for the period subperiod, O otherwise