Mastercard Vs. Visa: What's In Your Wallet?SummaryVisa is still the largest US credit card network. Mastercard has traded at a premium for some time due to its higher returns on equity and returns on invested capital.It appears a large part of the premium for Mastercard is due to accounting practice differences between Visa and Mastercard. Mastercard reduces its' equity capital base by not retiring shares.I prefer to look at margins versus returns on capital. If both used the same accounting for buybacks, the ROIC chasm would not be as large.Both have a similar emphasis on more B2B/C and G2C/B solutions is focused on international markets where digital payment systems are not yet commonplace among governments and businesses.Both are excellent businesses and somewhat insulated from defaults