I study the problem of a durable goods monopolist who lacks commitment power and whose marginal cost of production varies stochastically over time. I show that a monopolist with stochastic costs usually serves the different types of consumers at different times and charges them different prices....

"In modern times, international borders reflect discontinuous changes in political authority, no matter what the inconveniences are for the individuals that they separate. What explains this fact? Why are the citizens of neighboring regions that happen to lie across an international border often...