This report is a summary of A Reexamination of Who Wins and Who Loses from Credit Card Payments, which provides an in-depth analysis and reexamination of the theory explored by authors of the Federal Reserve Bank of Boston in 2010 that credit cards and credit card rewards programs lead to a regressive transfer of merchant costs at the point of sale. It examines how sensitive the Boston Fed staff report findings are to variations in the underlying assumptions and modifications to the accounting framework used.