The Retail-Minus Rule (RMR) specifies that the rate for a mandated wholesale service is set by subtracting from the vertically integrated provider's (VIP's) retail price the costs it avoids by selling the wholesale service rather than the retail service. While the RMR offers regulators an expedient method for setting wholesale prices, we show that it is efficient only under restrictive conditions. The proper test for a price squeeze inquires whether the VIP's retail price is greater than or equal to the sum of the direct cost and the opportunity cost of supplying the retail service. The RMR passes this test only when the competing retail services are perfect substitutes.

零售减法规则（RMR）规定，通过从垂直整合提供商（VIP）的零售价格中减去通过出售批发服务而不是零售服务而避免的成本，来设置强制性批发服务的费率。尽管RMR为监管机构提供了一种设定批发价格的便捷方法，但我们证明，该方法仅在限制性条件下有效。对价格挤压的正确测试是询问VIP的零售价格是否大于或等于直接成本和提供零售服务的机会成本之和。仅当竞争零售服务是完美替代品时，RMR才能通过此测试。