SAMPLE 1 20
READ(FIRM1.txt) YEAR IGM FGM CGM ICHR FCHR CCHR / SKIPLINES=1
READ(FIRM2.txt) YEAR IGE FGE CGE IWH FWH CWH / SKIPLINES=1
READ(FIRM3.txt) YEAR IUS FUS CUS  / SKIPLINES=1
* Stack the data
MATRIX I=(IGM'|ICHR'|IGE'|IWH'|IUS')'
MATRIX F=(FGM'|FCHR'|FGE'|FWH'|FUS')'
MATRIX C=(CGM'|CCHR'|CGE'|CWH'|CUS')'

SAMPLE 1 100
* Create cross-section dummy variables.
*  Set the number of cross-sections
GEN1 NC=5
MATRIX CSDUM=SEAS(100,-NC)
DO #=1,NC
 GENR D#=CSDUM:#
ENDO

* Pooling with AR1 errors and Panel-Corrected Covariance Matrix
POOL I F C D1-D5 / NOCONSTANT NCROSS=5 AR1 SAME HETCOV 
* Test for equality of firm intercepts
TEST
  TEST D1=D2
  TEST D1=D3
  TEST D1=D4
  TEST D1=D5
END
STOP