This Element offers a novel, highly relevant perspective towards Multilateral Development Banks (MDBs), which are development and financial organizations at the same time. Based on the elaborate institutional logics perspective borrowed from organizational sociology, it uncovers the complex trade-offs between financial and development pressures faced by MDBs and explains variation in organizational responses thereto across types of MDBs. The argument is tested with an original dataset using Data Envelopment Analysis to explain variation in response patterns across MDBs. The analysis shows that lending to the private sector as well as being predominantly owned by borrowing members increase MDBs' emphasis on the financial at the expense of the development nature. Thereby, this Element provides unique insights into MDBs' responses to their dual nature and significantly advances our understanding of MDB lending operations, drawing attention to the complexities involved in the unique MDB business model.

1. Introduction: the duality of MDBs; 2. Understanding MDBs; 3. Theorizing the dual nature of MDBs; 4. Analyzing institutional compliance; 5. Managing complexity; 6. Discussion; 7. Conclusion; Appendix; References.