The impact of sovereign credit ratings on Eurobond yields: Evidence from Africa

Abstract

The importance of sovereign credit ratings and Eurobonds issued by governments have come to the fore in Africa in the last decade. We examine whether changes in sovereign credit ratings impact Eurobond yields in 8 countries over the period of 2014–2019. Our approach reviews rating changes impact on Eurobond yields utilising the event study methodology. Our findings reflect that, on average, close to a third of rating actions directly impact bond yields in African countries. The statistically significant events include the downgrades of South Africa and Namibia to non-investment grade in 2017 reflecting critical transitions and bond investors’ reactions. Overall, the low percentage of a third, relative to previous international studies, suggests that largely rating changes are anticipated, do not have much new information and perhaps the perceived power of credit rating agencies may be overstated. In our view, the results reflect that pre-announcements of rating review dates since 2014 makes rating actions predictable and less impactful to bond yields. In addition, they reflect that bond investors adjust in real time as new information come in, resulting in less reliance on the opinions of CRAs and using their own assessments.