data(Becker94)
#### Fixed-effects model
## First stage analysis
fixed1 <- tssem1(Becker94$data, Becker94$n, method="FEM")
summary(fixed1)
## Prepare a regression model using create.mxMatrix()
A1 <- create.mxMatrix(c(0,0,0,"0.2*Spatial2Aptitude",
0,0,"0.2*Verbal2Aptitude",0,0), type="Full",
ncol=3, nrow=3, name="A1")
S1 <-
create.mxMatrix(c("0.2*ErrorVarAptitude",0,0,1,"0.2*CorBetweenSpatialVerbal",1),
type="Symm", name="S1")
## An alternative method to create a regression model using mxMatrix()
# A1 <- mxMatrix("Full", ncol=3, nrow=3, value=0, free=c(FALSE,FALSE,FALSE,TRUE,FALSE,
# FALSE,TRUE,FALSE,FALSE),
# label=c(NA,NA,NA,"Spatial2Aptitude",NA,NA,"Verbal2Aptitude",NA,NA),
# name="A1")
# S1 <- mxMatrix("Symm", ncol=3, nrow=3, value=c(0.5,0,0,1,0.2,1),
# free=c(TRUE,FALSE,FALSE,FALSE,TRUE,FALSE),
# label=c("ErrorVarAptitude",NA,NA,NA,"CorBetweenSpatialVerbal",NA),
# name="S1")
## Second stage analysis
fixed2 <- tssem2(fixed1, Amatrix=A1, Smatrix=S1, intervals.type="LB")
summary(fixed2)
#### Fixed-effects model: with gender as cluster
## First stage analysis
cluster1 <- tssem1(Becker94$data, Becker94$n, method="FEM", cluster=Becker94$gender)
summary(cluster1)
## Second stage analysis
cluster2 <- tssem2(cluster1, Amatrix=A1, Smatrix=S1, intervals.type="LB")
summary(cluster2)
#### Conventional fixed-effects GLS approach
## First stage analysis
## No random effects
## Replicate Becker's (1992) analysis using 4 studies only
gls1 <- tssem1(Becker92$data[1:4], Becker92$n[1:4], method="REM", RE.type="Zero",
model.name="Fixed effects GLS Stage 1")
summary(gls1)
## Fixed-effects GLS model: Second stage analysis
gls2 <- tssem2(gls1, Amatrix=A1, Smatrix=S1, intervals.type="LB",
model.name="Fixed effects GLS Stage 2")
summary(gls2)Run the code above in your browser using DataLab