How informative is the initial condition in the dynamic panel model with fixed effects?

I consider estimation of the autoregressive panel model with fixed effects yit=ci+βyi,t−1+εit. I investigate the estimation method developed by Blundell and Bond (1998), which makes use of the stationarity of the initial levels. I do it by numerically comparing the semiparametric information bounds for the case that incorporates the stationarity of the initial condition and for the case that does not. It is found that the efficiency gain can be substantial.