AAER (Adopt-Adapt-Expand-Respond) is a commonly used framework in market systems development (MSD) programming.
It originated from work between the Springfield Centre and the Katalyst programme in Bangladesh, and was written up in a paper by Nippard et al (2014) and in the second edition of the operational guide (Springfield 2015).
The initial paper introducing the framework described it as a tool for defining and assessing systemic change But the level of detail specified in the framework renders it more suited to narrative description of process stages often observed in systemic change. In practice, it is used mostly in narrative form, describing key stages in a process by which change happens in systems.
Jake Lomax's paper sets out the key problems inherent in having the main tool used for assessing and representing systemic change limited to narrative framing. He argues that with some relatively minor reframing of the concepts underlying AAER, the framework can be used effectively as an analytical tool that goes beyond storytelling to help us understand why systemic change happens.