The donor community has been increasingly concerned that development a
ssistance intended for crucial social and economic sectors might be us
ed directly or indirectly to fund unproductive military and other expe
nditures. The link between foreign aid and public spending is not stra
ightforward because some aid may be ''fungible.'' This article empiric
ally examines the impact of foreign aid on the recipient's public expe
nditures, using cross-country samples of annual observations for 1971-
90. For the base sample of 14 developing countries, it finds that aid
is not fungible at the aggregate level and there is no associated tax
relief Increasing the number of countries, however, makes aid fungible
. Moreover, results based on the main sample indicate that aid is fung
ible in three out of five sectors examined. Developing-country governm
ents receiving earmarked concessionary loans for agriculture, educatio
n, and energy reduce their own resources going to these sectors and us
e them elsewhere; only loans to the transport and communication sector
are fully spent on the purposes intended by donors. Because most aid
appears to be fungible, the rare of return on a specific donor-funded
project tells little about the impact of that assistance; a better app
roach may be to tie foreign aid to an overall public expenditure progr
am that provides adequate resources to crucial sectors.