I examine the use of nonlinear pricing as a method of price discrimination, both with monopoly and oligopoly supply. Topics covered include an analysis of when it is profitable to offer quantity discounts and bundle discounts, connections between second- and third-degree price discrimination, the use of market demand functions to calculate nonlinear tariffs, the impact of consumers with bounded rationality, bundling arrangements between separate sellers, and the choice of prices for quality upgrades and add-on products.
Peer-to-peer markets such as eBay, Uber, and Airbnb allow small suppliers to compete with traditional providers of goods or services. We view the primary function of these markets as making it easy for buyers to find sellers and engage in convenient, trustworthy transactions. We discuss elements of market design that make this possible, including search and matching algorithms, pricing, and reputation systems. We then develop a simple model of how these markets enable entry by small or flexible suppliers, and how they impact existing firms. Finally, we consider the regulation of peer-to-peer markets and the economic arguments for different approaches to licensing and certification, data, and employment regulation.