Does a currency union need a capital market union?
研究了四种货币联盟（分割市场、货币市场联盟、资本市场联盟、完全金融市场）在应对需求和供给冲击时的风险分担效率，发现货币市场联盟能有效分担国内需求冲击，而资本市场联盟对分担供给冲击必不可少。
We compare risk sharing in response to demand and supply shocks in four types of currency unions: segmented markets; a money market union; a capital market union; and complete financial markets. We show that a money market union is efficient at sharing domestic demand shocks (deleveraging, fiscal consolidation), while a capital market union is necessary to share supply shocks (productivity and quality shocks). In a numerical exercise, we find that the welfare gain of moving from segmented markets to a money market union is of roughly similar magnitude to that of moving from a money market to a capital market union.