というNBER論文が上がっている。原題は「An Event Study of COVID-19 Central Bank Quantitative Easing in Advanced and Emerging Economies」で、著者はJonathan S. Hartley(ハーバード大)、Alessandro Rebucci(ジョンズ・ホプキンス大)。

Amid the COVID-19 outbreak and related expected economic downturn, many developed and emerging market central banks around the world engaged in new long-term asset purchase programs, or so-called quantitative easing (QE) interventions. This paper conducts an event-study analysis of 24 COVID-19 QE announcements made by 21 global central banks on their local 10-year government bond yields. We find that the average developed market QE announcement had a statistically significant -0.14% 1-day impact, which is slightly smaller than past interventions during the Great Recession era. In contrast, the average impact of emerging market QE announcements was significantly larger, averaging -0.28% and -0.43% over 1-day and 3-day windows, respectively. Across developed and emerging bond markets, we estimate an overall average 1-day impact of -0.23%. We also show that all 10-year government bond yields in our sample rose sharply in mid-March 2020, but fell substantially after the period of QE announcements that we study in the paper.