The international development aid system is complex. Since its formation more than 60 years ago, it has developed incrementally rather than systematically over decades. No major institution has since exited from the system, while there has been a continued expansion that has resulted in increased complexity from the emergence of new donors, modalities and instruments. As multiple organisations provide aid over multiple topics through multiple relationships driven by multiple motivations, the aid system has now become very complex with a great deal of dynamic interaction between different agents. Recent issues arising from such complexities have fascinated researchers and decision-makers.
Studying such a system is not easy and there are many debates on how we should do so. With the progress of globalisation, our planet has become more and more connected. Thus, it is not surprising that there are many interwoven factors from both donor and recipient sides and even other global systems such as international trade, security and migration also interact with the international development aid system. Given the changing modern aid context, many researchers argue that the linear, mechanistic models and the assumptions on which aid is built are no longer inadequate in the dynamic, complex world we face today.
Although macroeconomic methods will still ...