  This paper examines experimentally how reputational uncertainty and the rate
of change of the social environment determine cooperation. Reputational
uncertainty significantly decreases cooperation, while a fast-changing social
environment only causes a second-order qualitative increase in cooperation. At
the individual level, reputational uncertainty induces more leniency and
forgiveness in imposing network punishment through the link proposal and
removal processes, inhibiting the formation of cooperative clusters. However,
this effect is significant only in the fast-changing environment and not in the
slow-changing environment. A substitution pattern between network punishment
and action punishment (retaliatory defection) explains this discrepancy across
the two social environments.
