  Despite considerable scholarly attention on the institutional and normative
aspects of development cooperation, its longitudinal dynamics unfolding at the
global level have rarely been investigated. Focusing on aid, we examine the
evolving global structure of development cooperation induced by aid flows in
its entirety. Representing annual aid flows between donors and recipients from
1970 to 2013 as a series of networks, we apply hierarchical stochastic block
models to extensive aid-flow data that cover not only the aid behavior of the
major OECD donors but also that of other emerging donors, including China.
Despite a considerable degree of external expansion and internal
diversification of aid relations over the years, the analysis has uncovered a
temporally persistent structure of aid networks. The latter comprises, on the
one hand, a limited number of major donors with far-reaching resources and, on
the other hand, a large number of mostly poor but globally well-connected
recipients. The results cast doubt on the efficacy of recurrent efforts for
"aid reform" in substantially changing the global aid flow pattern.
