This paper shows that if because of administration costs or other wast
es only a proportion of an aid reaches the recipient, then it is possi
ble that the donor is enriched by its act of charity, the extent of th
e enrichment increasing with the extent of the leakage, and/or that th
e recipient is impoverished by aid, the extent of the impoverishment i
ncreasing with the extent of the leakage. These outcomes are possible
even when trade is optimally restricted by donor or recipient.