The sovereign debt literature suggests the possibility that a self-fulfilling default crisis might be avoided if markets believe the central bank will act as lender of last resort. This paper investigates the extent to which changes in belief about an intervention of the European Central Bank (ECB) explain the sudden reduction of government bond spreads for the distressed countries in summer 2012. The authors study Twitter data and extract belief using machine learning techniques. They find evidence of strong increases in the perceived likelihood of ECB intervention and show that those increases explain subsequent decreases in the bond spreads of the distressed countries.

主权债务文献表明，如果市场相信中央银行将充当最后贷款人，则有可能避免自我实现的违约危机。本文调查了关于欧洲中央银行 (ECB) 干预的信念变化在多大程度上解释了 2012 年夏季陷入困境国家的政府债券利差突然减少。作者研究了 Twitter 数据并使用机器学习技术提取了信念。他们发现了欧洲央行干预可能性大幅增加的证据，并表明这些增加解释了陷入困境的国家债券利差随后下降的原因。