Much Ado About Nothing: Sovereign Ratings and Government Bond Yields in the OECD
IWH Discussion Papers,
In this paper, we propose a new method to assess the impact of sovereign ratings on sovereign bond yields. We estimate the impulse response of the interest rate, following a change in the rating. Since ratings are ordinal and moreover extremely persistent, it proves difficult to estimate those impulse response functions using a VAR modeling ratings, yields and other macroeconomic indicators. However, given the highly stochastic nature of the precise timing of ratings, we can treat most rating adjustments as shocks. We thus no longer rely on a VAR for shock identification, making the estimation of the corresponding IRFs well suited for so called local projections – that is estimating impulse response functions through a series of separate direct forecasts over different horizons. Yet, the rare occurrence of ratings makes impulse response functions estimated through that procedure highly sensitive to individual observations, resulting in implausibly volatile impulse responses. We propose an augmentation to restrict jointly estimated local projections in a way that produces economically plausible impulse response functions.
The Political Determinants of Sovereign Bond Yield Spreads
Journal of International Money and Finance,
This paper analyzes the political determinants of sovereign bond yield spreads using data for 27 emerging markets in the period 1996 to 2009. I find strong evidence that countries with parliamentary systems (as opposed to presidential regimes) and a low quality of governance face higher sovereign yield spreads, while the degree of democracy and elections play no significant role. A higher degree of political stability and the power to implement austerity measures significantly reduce sovereign yield spreads particularly in autocratic regimes, while no significant effect is detected for democratic countries. Overall, political determinants have a more pronounced impact on sovereign bond yield spreads in autocratic and closed regimes than in democratic and open countries.
Sovereign Credit Risk, Banks' Government Support, and Bank Stock Returns around the World: Discussion of Correa, Lee, Sapriza, and Suarez
Journal of Money, Credit and Banking, Vol. 46 (s1),
In the years leading up to the 2008–09 financial crisis, many banks around the world greatly expanded their balance sheets to take advantage of cheap and abundantly available funding. Access to international funding markets, in particular, made it possible for banks to reach a size that in some cases was a large multiple of their home countries’ gross domestic product (GDP). In Iceland, for example, assets of the banking system reached up to 900% of GDP in 2007. Similarly, by the end of 2008, assets in UK and Swiss banks exceeded 500% of their countries’ GDPs, respectively. Banks may also have grown rapidly because they may have wanted to reach too-big-to-fail status in their country, implying even lower funding cost (Penas and Unal 2004).
The depth and severity of the 2008–09 financial crisis and the subsequent debt crisis in Europe, however, have cast doubts on the ability of governments to bail out banks when they experience severe difficulties, in particular, in financially fragile environments and faced with large budget imbalances. This has resulted in as what some observers have dubbed a “doom loop”: the combination of weak public finances and weak banks results in a vicious cycle, in which the funding cost of banks increases, as the ability of governments to bail out banks is called into question, in turn increasing the funding cost of these banks and making the likelihood that the government will actually have to step in even higher, which in turn increases funding cost to the government and so forth.
Against this background, the paper by Correa et al. (2014) explores the link between sovereign rating changes and bank stock returns. They show large negative reactions of stock returns in response to sovereign ratings downgrades for banks that are expected to receive government support in case of failure. They find the strongest effects in developed economies, where the credibility of government bail outs is higher ex ante, while the effects are smaller in developing and emerging economies. In my view, the paper makes a number of important contributions to the extant literature.