Abstract
The chapter analyses the sovereign rating methodologies of DBRS, Fitch, Moody’s, and S&P. As a case study, we also replicate the four agencies’ model ratings (i.e. the basis of the rating committees’ qualitative assessment) to dissect the components of Italy’s ratings as of December 2020.
We find that rating processes and baseline methodologies are similar across the four agencies, whereas significant differences arise in terms of indicators and computational rules. As a result, model ratings—and, not unlikely, also the official ratings after the qualitative assessment—may diverge across the four agencies for the same sovereign issuer.
When we replicate the four agencies’ models for Italy, we find that the most favourable quantitative driver of the rating is the economy’s size as measured by GDP, which gets an AAA or equivalent score; additional economic strengths are the balanced external position and the solid institutional framework. The qualitative part of the rating, as described in the four agencies’ public reports on Italy, is instead driven by Italy’s risk factors which outbalance the assessment of some important sources of strength of the country (e.g. the 25-year track record of Government primary surpluses and the high private sector wealth).