We prove that under very weak conditions optimal financial products have to be co-monotone with the inverted state price density. Optimality is meant in the sense of the maximization of an arbitrary preference model, e.g. Expected Utility Theory or Prospect Theory. The proof is based on methods...

We present results from the rst large-scale international surveyon time discounting, conducted in 45 countries. Cross-country varia-tion cannot simply be explained by economic variables such as interestor ination rates. In particular, we nd strong evidence for culturaldierences, as measured by...