  Recent observations show a clear correlation between the probability of
hosting a planet and the metallicity of the parent star. Since radial velocity
surveys are biased, however, towards detecting planets with short orbital
periods, the probability-metallicity correlation could merely reflect a
dependence of migration rates on metallicity. We investigated the possibility,
but find no basis to suggest that the migration process is sensitive to the
metallicity. The indication is, therefore, that a higher metallicity results in
a higher probability for planet formation.
