the backbone function for the multilevelIV function
Usage
multilevelGMM(formula, endoVar, data = NULL)
Arguments
formula
an object of type 'formula': a symbolic description of the model to be fitted.
endoVar
a matrix or data frame containing the variables assumed to be endogenous.
data
optional data frame or list containing the variables of the model.
Value
returns the instrumental variables used in estimating the coefficients, variance-covariance matrix, the weight matrix used in estimating the model, etc.