Modularity, Transactions, and the Boundaries of Firms: A Synthesis
Executive Summary — For the last 30 years economists have used the concepts of "transaction," "transaction cost," and "contract" to illuminate a wide range of phenomena, including vertical integration; the design of employment, debt, and equity contracts; and the structure of industries. These concepts are now deeply embedded in the fields of economics, sociology, business, and law. Theories explain how to choose between different forms of transactional governance. But why does a transaction occur where it does? Without this answer, the forces driving the location of transactions in a system of production remain largely unexplored. This paper explains the location of transactions (and contracts) in a system of production. It also presents a theory of technological change that predicts changes in the location of transactions and therefore in the structure of industries. Key concepts include:
- Transaction locations are not technologically determined, but arise through the interplay of firms' strategies and knowledge and the requirements of specific technologies. Because strategies, knowledge, and technologies all change over time, the location of transactions changes as well.
- Each firm participating in a task network will have inexhaustible opportunities to gain advantage by redesigning the portions of the task network it controls and the transactions it influences.
- At the same time, new firms can quite easily attach themselves to the network at the boundaries of modules.
This paper constructs a unified theory of the location of transactions and the boundaries of firms. It proposes that systems of production can be viewed as networks of tasks. Transactions, defined as mutually agreed-upon transfers with compensation, are located within the task network and serve to separate one set of tasks from another. Placing a transaction in a particular location in turn requires work to define, count (or measure), and pay for the transacted objects. The costs of this work (labeled mundane transaction costs) are generally low at module boundaries and high in their interiors. Several novel implications arise from this work. Among these: Modularizations create new module boundaries, hence new transaction locations where entry and competition can arise. Areas in the task network where transfers are dense and complex should not be modularized. Instead these areas should be located in transaction-free zones so that the costs of transacting do not overburden the system. The boundaries of transaction-free zones constitute breakpoints where firms and industries may split apart.