Monopoly and trade policy
研究一国与外国垄断企业贸易时的最优政策选择，比较了进口配额、自愿出口限制、最低进口要求等工具的效果，发现不同成本条件下政策排名不同。
This paper derives trade policy rankings for a country trading with a foreign monopoly firm. It characterizes the first-best policy under decreasing monopoly costs, and itdemonstrates that a minimum import requirement implements first-best trade only under constant monopoly costs. The paper shows further that a voluntary import expansion eliminates all gains from trading with the monopoly, and that all quotas and voluntary export restraints are equivalent. Finally, it establishes that a price ceiling and a minimum import requirement are equivalent when monopoly costs are constant or decreasing, but that their ranking is ambiguous when costs are increasing.