Hi all!
I am working on estimating the
power analysis for the mediation model. I have a model similar to the
one presented by Donnelly et al. (2021) specifically the one of
moderated mediation (M = b1X + b2W + b3XW).
My problem is that I do not have a value for b1, b2 to use for the simulation. Instead I have a value for b1 - b2.
kappa.free <- kappa.pop <- matrix(NA, nrow = 2, ncol = 3,
dimnames = list(c("M","Y"), names(exoData)))
kappa.free["M","X"] <- "b1"
kappa.free["M","W"] <- "b2"
kappa.free["M","XW"] <- "b3"
kappa.free["Y","X"] <- "c1"
kappa.free["Y","W"] <- "c2"
kappa.free["Y","XW"] <- "c3"
## fill in population parameters
kappa.pop["M","X"] <- b1
kappa.pop["M","W"] <- b2
kappa.pop["M","XW"] <- b3
kappa.pop["Y","X"] <- c1
kappa.pop["Y","W"] <- c2
kappa.pop["Y","XW"] <- c3
(exoPaths <- bind(free = kappa.free, popParam = kappa.pop))
So, my problem is that I do not have a value for b1 or b2, but only for b1 - b2. Can I pass it into the kappa matrix somehow?
An alternative was to give a random number to b1 and then based on this estimate b2. Yet, I was thinking if is possible to not add restrictions beyond those implemented from the model.
Thanks a lot!
John