Defining family firms: A survey of empirical criteria
We survey 153 empirical studies of family firms and document 192 operational definitions representing 25 distinct definition types. These definitions can be decomposed into five recurring, codable dimensions: ownership, management, board representation, embeddedness, and succession. We relate these dimensions to economic mechanisms including agency conflicts, residual control rights, transaction costs, and dynastic control. Alternative definitions select systematically different populations and yield materially different estimates of firm performance and innovation. Definition choice is largely unrelated to the research question, except in succession studies. Ownership thresholds track private enforcement of self-dealing rules, but not statutory shareholder rights or rule of law. We conclude that the family firm is a family of related constructs rather than a single latent construct. Definitions should therefore match the family-firm construct implied by the research question, and results should be reported across alternative classification rules.