This note presents a simple graphical approach for deriving the profit maximizing two-part tariff when there are two types of consumers in the market. The exposition covers both the case in which a monopoly can offer only one two-part tariff plan and the case in which the monopoly can offer two different plans.
GotlibovskiC.KahanaN. (2009). Second-degree price discrimination: A graphical and mathematical approach. The Journal of Economic Education, 40(1), 68–79.