Hansen and Witkowski introduce a new theory to understand how societal needs are met. The authors develop the cross-sectoral BIAS theory, an adaptation of the BIAS model, to assess factors that lead to persistent unmet needs among marginalized populations. Drawing on postcolonial theory, the authors indicate that the standard economic model of understanding the provision of services by market, government, and nonprofit sectors (three-failures theory) systematically fails to account for the underprivileged in society. The cross-sectoral BIAS theory explains that societal biases drive the persistent insufficient provision of goods to marginalized populations by all three sectors.

In this concluding chapter, the editors take stock of the contributions, summarize overarching themes, and suggest new directions for research.

The chapter introduces readers to the major theories of the sector. Those covered include: market-failure theory, government-failure theory, contract-failure theory, voluntary-failure theory, supply-side (or entrepreneurship) theory, social-origins theory, interdependence theory, the commons, mediating structures, and associationalism.

This introductory chapter makes a case for the value of considering the role and purpose of nonprofits in society. It defines “theory” in accessible terms and describes the scope of nonprofit-sector theory. It also previews the subsequent chapters.