Kenneth W. Abbott is Jack E. Brown Chair in Law Emeritus at Arizona State University. Professor Abbott's research focuses on global governance institutions. He studies a wide range of public, private, and hybrid institutions and institutional complexes in fields including environment, health and corruption, and diverse governance modes, including intermediaries and orchestration. He received the inaugural Distinguished Scholar Award from the ISA International Law Section in 2017. Thomas J. Biersteker is Gasteyger Professor Honoraire at the Geneva Graduate Institute and a Public Policy Fellow at the Wilson Center in Washington. Professor Biersteker's research focuses on global governance, international sanctions, and dialectical approaches to IR theory. He concentrates on UN sanctions, has addressed the UN Security Council, and regularly briefs Security Council members on sanctions issues. He received the Professional Achievement Award from the University of Chicago in 2020.

'The role of informality in world politics is indisputable and yet rarely the subject of mainstream research. The contributors to this volume aim to change that. Their analysis of informal institutions, as well as informality's role in and around more formal institutions, is an important step toward better understanding the various dynamics through which global politics works.' Deborah Avant, Distinguished University Professor and Sié Chéou-Kang Chair, Josef Korbel School of International Studies, University of Denver

• Introduction: 1. Informality in global governance: an introduction Kenneth W. Abbott and Thomas J. Biersteker; Part I. Informality of Institutions: 2. From complex interdependence to complex governance Miles Kahler; 3. Soft pooling: how IIGOs govern collective decision-making without delegation Duncan Snidal and Felicity Vabulas; 4. Informal governance in the development regime: a political economy perspective on two types of informal organizations Bernhard Reinsberg; 5. Informal governance of international climate policy Axel Michaelowa, Katharina Michaelowa and Chandreyee Namhata; 6. Why do states cooperate informally? Comparing secret agreements in Europe and the Middle East Barbara Koremenos and Melissa Carlson; Part II. Informality Within Institutions: 7. International consequences of domestic politics: how divided government drives informal US influence in the World Bank Erasmus Kersting and Christopher Kilby; 8. Knowledge guardians in informal networks: how international organizations retain knowledge of strategic errors Heidi Hardt; Part III. Informality Around Institutions: 9. The role of transnational policy networks in informal governance: creating the office of the ombudsperson at the United Nations Thomas J. Biersteker; Part IV. Normative Issues: 10. Can informal governance promote procedural justice? Lora Anne Viola; Conclusion: 11. Conclusions: a research agenda on informal global governance Kenneth W. Abbott and Thomas J. Biersteker.

Kenneth W. Abbott is Jack E. Brown Chair in Law Emeritus at Arizona State University. Professor Abbott's research focuses on global governance institutions. He studies a wide range of public, private, and hybrid institutions and institutional complexes in fields including environment, health and corruption, and diverse governance modes, including intermediaries and orchestration. He received the inaugural Distinguished Scholar Award from the ISA International Law Section in 2017. Thomas J. Biersteker is Gasteyger Professor Honoraire at the Geneva Graduate Institute and a Public Policy Fellow at the Wilson Center in Washington. Professor Biersteker's research focuses on global governance, international sanctions, and dialectical approaches to IR theory. He concentrates on UN sanctions, has addressed the UN Security Council, and regularly briefs Security Council members on sanctions issues. He received the Professional Achievement Award from the University of Chicago in 2020.

'The role of informality in world politics is indisputable and yet rarely the subject of mainstream research. The contributors to this volume aim to change that. Their analysis of informal institutions, as well as informality's role in and around more formal institutions, is an important step toward better understanding the various dynamics through which global politics works.' Deborah Avant, Distinguished University Professor and Sié Chéou-Kang Chair, Josef Korbel School of International Studies, University of Denver

• Introduction: 1. Informality in global governance: an introduction Kenneth W. Abbott and Thomas J. Biersteker; Part I. Informality of Institutions: 2. From complex interdependence to complex governance Miles Kahler; 3. Soft pooling: how IIGOs govern collective decision-making without delegation Duncan Snidal and Felicity Vabulas; 4. Informal governance in the development regime: a political economy perspective on two types of informal organizations Bernhard Reinsberg; 5. Informal governance of international climate policy Axel Michaelowa, Katharina Michaelowa and Chandreyee Namhata; 6. Why do states cooperate informally? Comparing secret agreements in Europe and the Middle East Barbara Koremenos and Melissa Carlson; Part II. Informality Within Institutions: 7. International consequences of domestic politics: how divided government drives informal US influence in the World Bank Erasmus Kersting and Christopher Kilby; 8. Knowledge guardians in informal networks: how international organizations retain knowledge of strategic errors Heidi Hardt; Part III. Informality Around Institutions: 9. The role of transnational policy networks in informal governance: creating the office of the ombudsperson at the United Nations Thomas J. Biersteker; Part IV. Normative Issues: 10. Can informal governance promote procedural justice? Lora Anne Viola; Conclusion: 11. Conclusions: a research agenda on informal global governance Kenneth W. Abbott and Thomas J. Biersteker.