Search

This paper investigates the behaviour of credit rating agencies (CRAs) using a natural experiment in monetary policy. Specifically, we exploit the corporate QE of the Eurosystem and its rating-based specific design which generates exogenous variation in the probability for a bond of becoming eligible for outright purchases. We show that after the launch of the policy, rating upgrades were mostly noticeable for bonds initially located below, but close to, the eligibility frontier. In line with the theory, rating activity is concentrated precisely on the territory where the incentives of market participants are expected to be more sensitive to the policy design. Complementing the evidence on the effectiveness of non-standard measures, our findings contribute to better assessing the consequences of the explicit (but not exclusive) reliance on CRAs ratings by central banks when designing monetary policy.

On March 10, 2016, the European Central Bank (ECB) announced the Corporate Sector Purchase Programme (CSPP) - commonly known as corporate quantitative easing (QE) - to improve the financing conditions of the Eurozone's real economy and strengthen the pass-through of unconventional monetary interventions. Using a regression discontinuity design framework that exploits the rating wedge between the ECB and market participants, we show that: (i) bond yield spreads decline by around 15 basis points at the announcement of the programme, (ii) the impact is mostly noticeable in the sample of CSPP-eligible bonds that are perceived as high yield from the viewpoint of market participants and, (iii) the CSPP seems to have stimulated new issuance of corporate bonds. Overall, our results are consistent with the explanation that highlights the portfolio rebalancing mechanism and the liquidity channel.