data( "Kmenta" )
eqDemand <- consump ~ price + income
eqSupply <- consump ~ price + farmPrice + trend
system <- list( demand = eqDemand, supply = eqSupply )
## perform OLS on each of the equations in the system
fitols <- systemfit( system, data = Kmenta )
## all coefficients
coef( fitols )
coef( summary( fitols ) )
## coefficients of the first equation
coef( fitols$eq[[1]] )
coef( summary( fitols$eq[[1]] ) )
## coefficients of the second equation
coef( fitols$eq[[2]] )
coef( summary( fitols$eq[[2]] ) )
## estimation with restriction by modifying the regressor matrix
modReg <- matrix( 0, 7, 6 )
colnames( modReg ) <- c( "demIntercept", "demPrice", "demIncome",
"supIntercept", "supPrice2", "supTrend" )
modReg[ 1, "demIntercept" ] <- 1
modReg[ 2, "demPrice" ] <- 1
modReg[ 3, "demIncome" ] <- 1
modReg[ 4, "supIntercept" ] <- 1
modReg[ 5, "supPrice2" ] <- 1
modReg[ 6, "supPrice2" ] <- 1
modReg[ 7, "supTrend" ] <- 1
fitols3 <- systemfit( system, data = Kmenta, restrict.regMat = modReg )
coef( fitols3, modified.regMat = TRUE )
coef( fitols3 )
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