We characterize the classes of utility functions that are consistent with different notions of mean preserving spreads introduced in the literature. This gives rise to a unified approach and extension of some definitions of increasing risk, including the concepts of Rothschild and Stiglitz...

We extend the characterizations of increasing risks developed by Rothschild and Stiglitz (1970) to the case of unbounded probability distributions. We also consider the related notion of increasing risk about $\nu$ introduced by Landsberger and Meilijson (1990). Moreover, for some of the results...