The zonal response coefficient &kgr; and the tidal effective potential Love number k2 are two parameters which measure the amplitude of long-period earth tides. It is shown that reasonable models for the frequency dependence of Q in the mantle can result in an increase in the amplitude of these parameters of several percent. UT measurements of &kgr; at Mf Mm, and LAGEOS measurement of k2 at Ssa have uncertainties which are small enough to place valuable constraints on acceptable anelastic models. The LAGEOS measurement of the amplitude of the 18.6-year tide is not yet accurate enough to constrain further these models, but this situation will improve markedly as a larger fraction of an 18.6-year cycle is observed.