It's not a study, it's a letter that discusses one possible reason for this contribution.The San Francisco branch of the Federal Reserve (not a bastion of conservatism) did a study analyzing that question.
Why Is U.S. Inflation Higher than in Other Countries? - San Francisco Fed
Inflation rates in the United States and other developed economies have closely tracked each other historically. Problems with global supply chains and changes in spending patterns due to the COVID-19 pandemic have pushed up inflation worldwide. However, since the first half of 2021, U.S...
The letter even acknowledges other measures that reduce the level of contribution from direct assistance:
As Bianchi et al. (2021) point out, alternative modeling frameworks can result in different estimates. Barnichon et al. (2021), for example, indirectly find a much smaller, though statistically significant, contribution from fiscal measures using historical U.S. data and relying on a new measure of labor market slack.
Of course, if we had already had a level of personal assistance similar to other OECD countries, the assistance in the ARP wouldn't have been needed.