Table 1.

Comparative statics of the equilibrium analysis. These describe how optimal contact rates vary with the other parameters, evaluated under the assumption that a symmetric Nash equilibrium exists such that ${\beta }_i={\beta }_H$ for all healthy and ${\beta }_i={\beta }_S$ for all sick. See Supplementary Information ‘Comparative Statics Derivations’ for details.

A marginal increase in ...	... leads to ...
Social distancing of healthy	Less social distancing of sick
Social distancing of sick	Less social distancing of healthy
Size of the healthy population	More social distancing of sick${}^{!}$
Size of the sick population	More social distancing of healthy${}^{!}$
Pro-social concern of the sick	More social distancing of sick
Dear of disease of the healthy	More social distancing of healthy*

*Present in the model by Ref.⁴⁵. The other effects are new

${}^{!}$Contrary to imitation, herding, etc. as proposed, for example, in^11,59.