Isoelastic utility

In economics, the isoelastic function for utility, sometimes isoelastic utility function, is used to express utility in terms of consumption.

It is

$u(c)={\frac {c^{1-\eta }}{1-\eta }}$

where $c$ is consumption, $u(c)$ the associated utility, and $\eta$ a constant (if $\eta =1$ it is conventional to use the limiting value, viz $u(c)=\log c$).

The isoelastic function is used in the Stern review, page 52.