  We evaluate new observational constraints on the two-parameter
scale-dependent spectral index predicted by the running-mass inflation model by
combining the latest Cosmic Microwave Background (CMB) anisotropy measurements
with the recent 2dFGRS data on the matter power spectrum, with Lyman $\alpha $
forest data and finally with theoretical constraints on the reionization
redshift. We find that present data still allow significant scale-dependence of
$n$, which occurs in a physically reasonable regime of parameter space.
