Formal organizations and markets constitute the basic forms of the economy. In social science a sharp distinction has usually been made between these forms, even treating them as opposites, and the study of them has been concentrated in different disciplines. We argue that such a perspective is rarely useful. Markets and organizations share at least one characteristic: they are both organized. We define market and organization and describe how markets and formal organizations are connected and similar in several respects. We present questions about the organization and reorganization of markets that will be discussed in the book, and the way we have used empirical examples in our analyses. Finally, we provide an overview of the rest of the book.