“…This issue has been mainly addressed with regard to possible decreasing marginal returns to aid, evidenced by the positive coefficient of the aid variable combined with the negative coefficient of its squared value. Several studies had found such results (beginning by Burnside and Dollar 2000, Collier and Dollar, 2001, 2002, Hansen and Tarp 2000, 2001, Lensink and White 2000, with a corresponding threshold where the marginal contribution of aid to growth becomes nil, which reflects limited absorptive capacity for aid (see Feeny and de Silva, 2013, for a recent contribution). Besides, an upper threshold due to absorptive capacity, there may be also a minimum level of aid needed for effectiveness, justifying the need for a "big push" (Gomanee et al 2003, Guillaumont andGuillaumont Jeanneney 2010).…”