效率兼顾公平兰姆塞规则是效率原则，他完全不考虑如何在税制设计中体现公平原则这一问题。对这一缺点，米尔利斯与戴尔蒙在70年代初的研究中作了改进。戴尔蒙与米尔利斯合作在1971年的《美国经济评论》(AmericanEconomicReview)上连续发表了两篇论文，即《最优税收与公共生产 Efficiency and Fairness Lambert’s rule is the principle of efficiency. He does not consider how to reflect the principle of fairness in tax design. In response to this shortcoming, Millice and Delmont made improvements in their research in the early 1970s. In a 1971 American Economic Review, Del Monte collaborated with Millis to publish two consecutive papers entitled "Optimal Taxation and Public Goods Production