There is growing interest in ways in which donors can be influenced. While there is some nascent literature on how behavioural insights can be used to influence policy makers (see Helpdesk report, no. 1426), there is very limited research and evidence on the ways in which donors influence other donors. Based on the available literature, this report focuses in large part on descriptive research on influencing multilateral development agencies (much of which is focused on DFID) and on triangular (or trilateral) cooperation, involving emerging donors.