Inoue, A., and Gary Solon. 2006. "A Portmanteau test for serially correlated errors in fixed effects models." Economic Theory, 22(5): 835-851.
We propose a portmanteau test for serial correlation of the error term in a fixed effects model. The test is derived as a Lagrange multiplier test, but it also has a straightforward Wald test interpretation. In Monte Carlo experiments, the test displays good size and power properties.