While the ostensible purpose of aid is to promote the development of recipient countries, it has long been observed that donor aid policy is influenced by commercial and political interests. A number of recent studies have contributed to this research by estimating the economic benefits, to a donor, of its aid budget. Some of the evidence for the UK, using what we term the net resource cost approach, is briefly set out. A recent study of Irish aid, using an opportunity costs approach, suggests that aid does impose a real resource cost on the Irish economy. Applying the net resource cost approach, on the other hand, suggests that the benefits to Ireland in terms of the level of economic activity supported could well equal expenditure on aid. The evidence is used to argue for increased aid with greater emphasis on development.