Trinity College Dublin

Skip to main content.

Top Level TCD Links

Courage to Capital? A Model of the Effects of Rating Agencies on Sovereign Debt Roll–over

Galina Hale

With the rise of international bond markets in the 1990s, the role of sovereign credit ratings has become increasingly important. In the aftermath of Asian Crises a series of empirical studies on the effects of sovereign ratings appeared. The theoretical literature on the topic, however, remains rather scarce. We propose a model of rating agencies that is an application of global game theory in which heterogeneous investors act strategically. The model is consistent with the main findings of the empirical literature. In particular, it is able to explain the independent effect of sovereign ratings on the cost of debt. Our model also predicts that, in addition to affecting the level of debt roll–over, the mere existence of the rating agency's announcement can increase the magnitude of the response of capital flows to changes in fundamentals. In addition, introducing a rating agency to a market that otherwise would have the unique equilibrium can bring multiple equilibria. The model also allows us to explore the reasons why agencies may over–react to crises, how they can spread financial contagion, and the failure of rating agencies to predict crises.

Key words: credit rating, rating agency, sovereign debt, global game
JEL classification: F34, G14, G15

Last updated 28 August 2014 by IIIS (Email).