  We study the connection between risk aversion, number of consumers and
uniqueness of equilibrium. We consider an economy with two goods and $c$
impatience types, where each type has additive separable preferences with HARA
Bernoulli utility function,
$u_H(x):=\frac{\gamma}{1-\gamma}\left(b+\frac{a}{\gamma}x\right)^{1-\gamma}$.
We show that if $\gamma\in \left(1, \frac{c}{c-1}\right]$, the equilibrium is
unique. Moreover, the methods used, involving Newton's symmetric polynomials
and Descartes' rule of signs, enable us to offer new sufficient conditions for
uniqueness in a closed-form expression highlighting the role played by
endowments, patience and specific HARA parameters. Finally, new necessary and
sufficient conditions in ensuring uniqueness are derived for the particular
case of CRRA Bernoulli utility functions with $\gamma =3$.
