Il ruolo dell’asimmetria riguardo le preferenze

This work is about the role of asymmetry in distribution of portfolio returns and preferences of investors. It is known that skewness of distribution can play some roles about preferences but usually in economic theory this role is merged with the concept of utility function, and in particular with expected utility maximization. This perspective seems me unsatisfactory in two respects. Firstly the financial intuition behind the opportunity of consider asymmetry become too abstract and difficult to grasp for practitioners. Secondly this strategy work only if the third moment exist, this is not a weak assumption for financial returns. Here we suggest another strategy. It takes in consideration the comparison between mean and median of return distribution. So we achieve a representation that give us an intuition about the opportunity of consider with favour positive asymmetry and with disfavour negative one. The main advantage of this representation is that it involves probabilistic concepts only (no utility theory) and it is easy to understand and communicate for practitioners too. Moreover in this way the existence of third moment is not required, first one it is enough.