This Project Briefing examines an attempt by the ODI to develop and apply a framework to enhance measurement of the net benefits of different options for aid delivery in Malawi by the UK Department for International Development (DFID) -- an options appraisal. It looks at why DFID has strengthened its economic appraisal and summarises the methodology and findings from Malawi. Finally, it considers the implications for operational practice and gives recommendations for the design of options appraisals in the future. The research suggests that, according to the Malawi options appraisal framework, General Budget Support (GBS) is the marginally preferred aid modality. The Malawi appraisal is a good starting point for the development of a more robust appraisal model for wider use.