The small-sample bias of the ordinary least-squares coefficient estima
tor for dynamic regression models with innovation errors and lagged-de
pendent and strongly-exogenous explanatory variables is approximated t
hrough both small disturbance and large-sample asymptotics. Results fo
r the standard ARMAX(p, 0, k) model are obtained and also for such mod
els under linear parameter constraints and variable transformations. T
hese approximations are then used to construct corrected estimators fo
r the parameters of interest in higher-order dynamic models, including
the empirically highly relevant linear error-correction model. By sim
ulating two empirical cases the corrected estimators obtained via larg
e-sample asymptotics are shown to have more attractive location and ef
ficiency properties than ordinary least-squares.