  Recent work in iterative voting has defined the additive dynamic price of
anarchy (ADPoA) as the difference in social welfare between the truthful and
worst-case equilibrium profiles resulting from repeated strategic
manipulations. While iterative plurality has been shown to only return
alternatives with at most one less initial votes than the truthful winner, it
is less understood how agents' welfare changes in equilibrium. To this end, we
differentiate agents' utility from their manipulation mechanism and determine
iterative plurality's ADPoA in the worst- and average-cases. We first prove
that the worst-case ADPoA is linear in the number of agents. To overcome this
negative result, we study the average-case ADPoA and prove that equilibrium
winners have a constant order welfare advantage over the truthful winner in
expectation. Our positive results illustrate the prospect for social welfare to
increase due to strategic manipulation.
