This literature review examines six research topics which explore ways to improve the effectiveness of aid modalities. Drawing on the discussions and comments at ODI's 2011 meeting series on the future of budget support, six topics for research to improve the range of policy options for delivering aid at the country level were identified:

• Building a new typology of existing (and emerging) aid instruments.
• Understanding recipient government perceptions of effective aid instruments.
• Embedding political economy insights in aid instrument design.
• Designing portfolios of complementary aid instruments
• Comparing the fiduciary risks of different aid instruments.
• Designing better frameworks for aid delivery options.

This literature review examines the relevant research that currently exists for each of these topics. It explores the key findings and main messages in the existing literature. In doing so it assesses whether the proposed research topic duplicates existing research or does in fact propose to explore a new set of issues.