Aid Evaporation is a new Nortion. It is based on an academic study that comprehensively examined how ODA is governed from the source to the destination. Key ODA parameters emerged from the existing ODA governance frameworks namely; mechanism, ideology, development approach and processes. By unpacking elements contributing to aid ineffectiveness through these parameters, exploring the existence of the aid evaporation and examining the key enablers of ODA Evaporatoon, the study discovered supply side factors contributed significantly to Aid ineffectiveness. It exposed different AID Evaporation enablers which play different hidden functions such as ODA Door Openers, Appetixers, Softeners, Sponges, Convertors, Controllers, Distorters as well as Carrot and Stick among others. Key findings revealed that the prevailing perception that aid ineffectiveness was a demand side problem was only part of the story because supply side challenges were probably more responsible for billions of ODA that could not be accounted for. It has recommended the re-writing of the narrative that ODA ineffectiveness is predominantly premised on demand side by incorporating supply side factors. Findings demonstrated that while there were indeed demand side challenges such as bad governance, corruption and lack of strong institutions, there were also supply (donor) side challenges such as over-reliance of donor's own inefficient ODA governance frameworks as well as ODA delivery mechanisms, the entrenchment of bilateral interest in ODA processess and geo- political interests among other factors. In this regard, the study confirmed that the 62% of the ODA that could not be accounted for according to existing literature was either held up in the pipeline or evaporates mostly from the supply side. This finding brought clarity on the weak impact of ODA and corroborated with existing literature on the mystery of unaccounted ODA. While the notion of aid evaporation emerged as an attribution and part of a reflection on the problem of ODA dissipation at the preliminary stage of the literature review, it became the central issue of focus throughout the research investigation which involved substantive field work to bring clarity on the problem. The study has made theoretical and practical contributions to the existing concepts on ODA governance and proposed a new concept, namely the “Supply Baggage Concept”. The new concept should inform the Post Paris era in achieving Aid effectiveness by weding out Evaporation, using the Aid Evaporation Detection Framework proposed in this book.