*
* CHOW2.RPF
* RATS Version 8, User's Guide, Example 3.4
* Chow test by dummied regressors
*
open data states.wks
data(org=obs,format=wks) 1 50 expend pcaid pop pcinc
set pcexp = expend/pop
set large = pop>=5000      			   ;* Will be one for large states
*
* Set up dummies for PCAID and PCINC
*
set dpcaid = pcaid*large
set dpcinc = pcinc*large
*
* Compute regression with dummies
*
linreg(robusterrors) pcexp
# constant pcaid pcinc large dpcaid dpcinc
*
* Test dummies
*
exclude(title="Sample Split Test-Robust Standard Errors")
# large  dpcaid  dpcinc