Vertical Integration and Firm Boundaries : The Evidence

Understanding what determines firm boundaries and the choice between interacting in a firm or a market is not only the fundamental concern of the theory of the firm, but it is also one of the most important issues in economics. Data on value added, for example, reveal that in the US, transactions that occur in firms are roughly equal in value to those that occur in markets. The economics profession, however, has devoted much more attention to the workings of markets than to the study of firms, and even less attention to the interface between the two. Nevertheless, since Coase’s (1937) seminal paper on the subject, a rich set of theories has been developed that deal with firm boundaries in vertical or input/output structures. Furthermore, in the last 25 years, empirical evidence that can shed light on those theories has been accumulating.