Disk heating and stellar migration in galaxies
  The paper claimed that significant radial migration of stars in a stellar disk like that of the Milky Way could not occur. We now think that while the treatment of the effects of molecular clouds was correct, the paper seriously underestimated the ability of spiral arms to shift the radii of stars that corotate with them. Consequently, it is likely that significant radial migration_is_ possible. 
J. J. Binney and J. A. Sellwood