  We analyze the effect of cultural drift, modeled as noise, in Axelrod's model
for the dissemination of culture. The disordered multicultural configurations
are found to be metastable. This general result is proven rigorously in d=1,
where the dynamics is described in terms of a Lyapunov potential. In d=2, the
dynamics is governed by the average relaxation time T of perturbations. Noise
at a rate r < 1/T induces monocultural configurations, whereas r > 1/T sustains
disorder. In the thermodynamic limit, the relaxation time diverges and global
polarization persists in spite of a dynamics of local convergence.
