Adherence: A Behavioral Economists' View

2. Related Literature

Until now there is little theoretical research in economics focusing on adherence. Egan and Philipson (2014) interpret the decision for non-adherence as an optimal stopping problem, where patients learn their individual specific value of a treatment through experience. Mealem et al. (2012) describe the situation as a principal-agent-relationship between physician and patient. But both approaches assume that there are individual costs of sticking to a treatment that turn non-adherence to a perfectly rational and correct choice for the patients. In this case non-adherence should not be regarded as a problem at all and would rather reflect the physicians' ignorance of the patients' specific condition. Djawadi et al. (2014) developed a theory recognizing this and test it in the lab. Their paper is briefly sketched in Section 5.

Another stream of research accepting that a patient’s decision to be non-adherent may not be in her own best interest is the literature on addiction. It is extremely relevant for our topic, if the medical advice is to refrain from something like taking drugs or overeating. Of course here as well is the theory of rational addiction developed by Becker and Murphy (1988), but there are also different approaches. First of all dynamic inconsistency of choices may drive a patient to non-adherence.²