[R] random coefficients in R - simultaneity in panel data

[zubin]

hello - using SAS proc mixed to estimate random coefficients - R has a
similar command.  However, i need to estimate random coefficients when there
exists Simultaneity bias in the cross sectional time series panels  -
specifically 

Simultaneity, endogeneity, and lagged dependent variables in panel data.

anyone can steer me to an R function or such that can help?