  A spectral index n_s < 0.95 appears to be a generic prediction of racetrack
inflation models. Reducing a general racetrack model to a single-field
inflation model with a simple potential, we obtain an analytic expression for
the spectral index, which explains this result. By considering the limits of
validity of the derivation, possible ways to achieve higher values of the
spectral index are described, although these require further fine-tuning of the
potential.
