Everything should be evidence-based - if only the evidence would make up its mind already
This question came up on an Evaluation mailing list and was forwarded to non other than Andrew Gelman, and for our purposes it can be boiled down to: what do we really know about financial motivation in organisations? Do we know enough to be able to say something like “in this case use this reward system, it will bring you optimal results”?
Reading through the illustrious answers it seems clear that there are dozens of different theories and variations of theories, each with some research evidence, but nowhere anything like an evidence-backed consensus.
Policy, project and programme design, …. everything should be evidence-based - if only the evidence would make up its mind already.
Motivation and reward are comparatively easy to conceptualise and research. If we can’t get consensus here, how are we going to get consensus with hundreds of harder real-world problems like “how much should cash programmes after a natural disaster target women? - single women? how much? family size? conditionality?”
How can we construct Theories of Change if there is such a lack of consensus about what leads to what?