It surprises no one that the rich save more. But they save even more than what could be accounted for the lower propensity to consume that one would get from any reasonably parametrized model. What could account for the difference?
Annamaria Lusardi, Pierre-Carl Michaud and Olivia Mitchell that survey evidence tends to indicate that the rich are financially more literate, whereby the direction of the causality is not clear. They build a life-cycle model where financial literacy is endogenous. The mechanism generating higher savings is interesting. As the rich get retirement benefits that are relatively small compared to their permanent income, they need to have more precautionary savings. To manage these savings, they get more financially literate. This allows them to get higher returns and get even richer, while those that are content with their public retirement package see no need to save more and learn how to get better returns. One more reason to improve economic literacy in the public.