We present a sequential approach to estimating a dynamic Hausman-Taylor model. We first estimate the coefficients of the time-varying regressors and subsequently regress the first-stage residuals on the time-invariant regressors. In comparison to estimating all coefficients simultaneously, this two-stage procedure is more robust against model misspecification, allows for a flexible choice of the first-stage estimator, and enables simple testing of the overidentifying restrictions. For correct inference, we derive analytical standard error adjustments. We evaluate the finite-sample properties with Monte Carlo simulations and apply the approach to a dynamic gravity equation for US outward foreign direct investment. 1 Schooling itself is a time-invariant regressor in his data set. Yet it is hard to argue that its coefficient is identified because Andini uses only the first differences of time-varying regressors as instruments. These instruments are generally assumed to be uncorrelated with any time-invariant variable. 526 2 Plümper and Troeger (2007) proposed a three-stage approach for the static model that they label "fixed effects vector decomposition." In a symposium on this method, Breusch, Ward, Nguyen, and Kompas (2011) and Greene (2011) show that the first two stages can be characterized by an instrumental variables estimation with a particular choice of instruments, and that the third stage is essentially meaningless. 3 Hoeffler (2002) argues similarly. 4 As Binder, Hsiao, and Pesaran (2005) and Bun and Windmeijer (2010) emphasize, GMM estimators might suffer from a weak instruments problem when the autoregressive parameter approaches unity or when the variance of the unobserved unit-specific effects is large. Moreover, the number of instruments can rapidly become large relative to the sample size. The consequences of instrument proliferation, summarized by Roodman (2009), range from biased coefficient and standard error estimates to weakened specification tests. 5 Our two-stage procedure fits into the framework of sequential estimators discussed by Newey (1984). While our paper is only concerned with linear panel data models, Honoré and Kesina (2017) recently suggested related two-stage approaches for some nonlinear models. They use a bootstrap procedure to obtain valid standard errors in contrast to our analytical standard error correction.