“…13 Fourth, in part of the analysis, private and public aid are allowed to have differential effects on the recipient country. The literature has treated foreign aid as a public good (see, for example, Olson and Zeckhauser, 1966;Dudley, 1979). Olson and Zeckhauser (1966) proposed a theory of alliances to explain the allocation of defense expenditures among Western nations in NATO.…”