Claude M. Setodji, Michael Shwartz, Fixed-effect or Random-effect Models: What are the Key Inference Issues?, Medical Care, Vol. 51, No. 1 (January 2013), pp. 25-27 ...

However, prior studies assume that all available covariates and random-effect components are independent of the model error, which is often violated (endogeneity) in practice. In this study, we first ...