TY - JOUR TI - Simple solutions to the initial conditions problem in dynamic, nonlinear panel data models with unobserved heterogeneity AU - Jeffrey M. Wooldridge JO - Journal of Applied Econometrics PY - 2005 VL - 20 IS - 1 DO - 10.1002/jae.770 UR - https://doi.org/10.1002/jae.770 ER -