'------------ Nonlinear SUR Estimation ------------ 
INPATH C:\Program Files\Betahat4.0
OPEN POOL20.DT1
USE 1 20

'Define equations.
GE_EQ_NL.NLS             GE_INVEST             B1*CONSTANT+B2*GE_VALUE+B3*GE_STOCK      / NOESTIMATE 
WEST_EQ_NL.NLS      WEST_INVEST      B4*CONSTANT+B5*WEST_VALUE+B6*WEST_STOCK    / NOESTIMATE 
GM_EQ_NL.NLS            GM_INVEST             B7*CONSTANT+B8*GM_VALUE+B9*GM_STOCK      / NOESTIMATE
CHRY_EQ_NL.NLS       CHRY_INVEST        B10*CONSTANT+B11*CHRY_VALUE+B12*CHRY_STOCK    / NOESTIMATE
STEEL_EQ_NL.NLS     USSTEEL_INVEST B13*CONSTANT+B14*USSTEEL_VALUE+B15*USSTEEL_STOCK / NOESTIMATE

   'Estimate nonlinear SUR.
SYSTEM GE_EQ_NL WEST_EQ_NL GM_EQ_NL CHRY_EQ_NL STEEL_EQ_NL