The article explains how financial crises can spread between countries through their sovereign debt markets. By studying the behavior of investors and the connections between economies, the researchers found that when one country defaults on its debts, it can affect the risk tolerance of investors, leading to a contagion effect on other countries with weaker fundamentals. This can result in a "flight to quality" where investors move their money to safer countries. The model developed by the researchers was able to accurately predict the spread between sovereign bonds and riskless assets, the correlation between economies' bond spreads, debt flows, and consumptions, and the increased volatility during times of financial crisis in emerging economies.