  We consider the lifetimes of metastable states in bistable evolutionary games
(coordination games), and examine how they are affected by spatial structure. A
semiclassical approximation based on a path integral method is applied to
stochastic evolutionary game dynamics with and without spatial structure, and
the lifetimes of the metastable states are evaluated. It is shown that the
population dependence of the lifetimes is qualitatively different in these two
models. Our result indicates that spatial structure can accelerate the
transitions between metastable states.
