Mastercard interchange rates are established by Mastercard, and are generally paid by acquirers to card issuers on purchase transactions conducted on Mastercard cards. Interchange rates are only one of many cost components included in a MDR, and are a necessary and efficient method by which Mastercard maintains a strong and vibrant payments network. Setting interchange rates is a challenging proposition that involves an extremely delicate balance. If interchange rates are set too high, such that they lead to disproportionately high MDRs, merchants' desire and demand for Mastercard acceptance will drop. If interchange rates are set too low, card issuers' willingness to issue and promote Mastercard cards will drop, as will consumer demand for such cards. In response to these competitive forces, we strive to maximize the value of the Mastercard system (including the dollars spent on Mastercard cards, the number and types of cards in circulation, and the number and types of merchants accepting Mastercard cards) by setting default interchange rates at levels that balance the benefits and costs to both cardholders and merchants.