Chapter 10 identifies 21 variants of the good-faith purchase doctrine, which are often different combinations of several key factors. That said, none of the 21 schemes are the most efficient. Among the forms of good-faith purchase doctrine currently in use, the market overt rule comes closest to ex ante efficiency because original owners, merchant dealers, and consumers all have incentives to spend close to optimal costs on verification and prevention, and the movables in question are more likely to be in the hands of higher valuers. Drawing on mechanism design literature, Chapter 10 argues that when both an original owner and a consumer are non-negligent, the two parties can be assigned 50% shares of the movable in question, and an ensuing internal auction between them can ex post tease out who values the resource more. This internal auction design is inexpensive to administer.

Sale was central to the trade in manufactured goods but hire and hire purchase were also used for the marketing of some goods such as railway wagons, motor vehicles and lorries. With sale the common-law rules, later codified in the Sale of Goods Act 1893, might be altered in the written contract if they failed to accord with commercial need. In practice the default rules and the terms of any written contract worked in the context of the relationship between the manufacturer and purchaser whether, for instance, it was long term and whether trust remained or had evaporated. These written contracts were vital if the contract contained detailed specifications as to how an item was to be made. What happened when things went wrong might be more informal, without resort to lawyers or law. Hire and hire purchase meant customers obtained manufactured goods on credit; on the other, suppliers had some protection through a form of quasi-security if customers defaulted in their payments, or the goods were wrongly disposed of. Manufactured goods could be distributed through commercial intermediaries who were allocated geographical areas to market them and bound to do that at specific prices and in specific ways.