Differentiability of von Neumann–Morgenstern utility functions

This paper studies necessary and sufficient preference-based conditions for differentiability of risk averse (prudent, or temperate) von Neumann–Morgenstern utility functions. The very idea to devise those conditions is based on the reverse claim of an old observation by Arrow that a risk-averse expected-utility maximizer will always accept a sufficiently small stake in any positive expected-value bet if her von Neumann–Morgenstern utility function is differentiable.     

A necessary and sufficient condition for the positivity of the growth rate in the Neumann–Gale model of economic growth

In the paper I will discuss an extension of the classical problem of the positivity of the growth rate in the Gale–Neumann model. I will show that the exploitation of the labour is a necessary and sufficient condition for the positivity of the growth rate.