Country Solidarity in Sovereign Crises
研究了国家间在主权危机中自发产生的团结如何通过契约强化，分析了不同风险国家间最优债务合约的设计，发现联合责任仅在特定条件下才最优。
When will solidarity, which emerges spontaneously from the fear of spillovers, be reinforced through contracting? The optimal pact between countries that differ substantially in their probability of distress is a simple debt contract with market financing, a borrowing cap, but no joint liability. While joint liability augments total surplus, the borrowing country cannot compensate the deep-pocket guarantor. By contrast, the optimal pact between two countries symmetrically exposed to shocks with an arbitrary correlation is a simple debt contract with joint liability, provided that shocks are sufficiently independent, spillovers sufficiently large, liquidity needs moderate, and available sanctions sufficiently tough.