Donors play an important role in promoting political reform in Africa, and democracy aid represents an increasing proportion of donor portfolios. Yet there remains uncertainty about the effectiveness of this spending; and many argue that aid can undermine democratic processes by weakening accountability relationships or by fuelling patronage spending. Building upon their previous path-breaking contributions, Nicolas van de Walle and Danielle Resnick's edited volume takes on these debates and provides a fascinating account of the impact of donors on democratic processes across seven states.

One of this book's analytical contributions is the authors’ decision to separate effects across components of reform – such as improvements in horizontal versus vertical accountability. They rightly argue that different types and modalities of aid are likely to differentially affect these outcomes. The authors also do a thorough job summarising research to date, and teasing out possible mechanisms of donor influence, with a particular focus on the role of norms, material incentives and coercion.

The book begins with a careful cross-national evaluation by Simone Dietrich and Joseph Wright. Especially useful is the way these authors test effects across different channels of democratisation and consolidation, such as multiparty transitions, multiparty failure and incumbent turnover. This chapter confirms that both economic and democracy aid is correlated with multi-party transitions. However Dietrich and Wright are unable to find much evidence that aid contributes to democratic consolidation.

The seven case studies expand on these findings by evaluating when and why aid might have impacted political processes. Many readers will appreciate the fact that these authors evaluate the impact of aid in light of recent shifts in aid modalities and the rise of non-traditional donors, such as China. These case studies vary in their verdict. The authors show that donor conditionality was quite successful in coercing Hastings Banda to allow multiparty elections in Malawi and persuading the Frelimo government to reform the electoral laws in Mozambique. However they point to several failures, such as Mali's military takeover in 2012 and support for political patronage in Tanzania.

The authors’ derive some important lessons: They note that economic aid is occasionally successful at influencing multiparty transitions, particularly when donors have economic leverage. They also note the importance of democracy aid for funding electoral processes. The authors are more pessimistic – though not hopeless – about donor efforts to promote horizontal accountability or to prevent democratic backsliding. They note that donors have a history of bypassing legislatures, and may therefore contribute to executive dominance over policymaking. They also raise concerns throughout the book about how donor fragmentation limits policy leverage, particularly since non-traditional donors sometimes fail to share the concerns of the rest of the donor community.

There are challenges. Some chapters could make a stronger case for causation, and I occasionally wonder whether donors are getting credit for an emerging liberalisation process, rather than for an effect of aid on reforms. For similar reasons, it would also have been useful to know more at points about why decisions were made by donors to target aid in a particular way and to particular places. But this book is an improvement over much of the empirical work on aid and democratisation, and a helpful update on contemporary issues. Scholars and practitioners interested in Africa's democratisation process and the political effects of aid will find this well worth reading.