Optimal pricing by a monopoly airline that faces capacity constraints during the peak demand period is studied. The existence of capacity constraints means that in order to expand output the airline must divert demand from the peak period to the off-peak period. A particular advance-purchase discount policy is shown to be the profit-maximizing method of selling tickets. If the advance-purchase requirement were infeasible, output and total surplus would both be lower.

Yeon-Koo Che and Ian Gale (1998) studied the impact of imposing a cap on lobbying expenditures. They showed that a cap may lead to (1) greater expected aggregate expenditures and (2) a less efficient allocation of a political prize. In their comment, Todd Kaplan and David Wettstein (2005) show that if the cap is not rigid (i.e., its effect on the cost of lobbying is continuous) it has no effect.