Self control and intertemporal choice: Evidence from glucose and depletion interventions. CESifo Working Paper #4609

Abstract: How relevant are resource-based models of willpower for financial choice? We estimate the effects of three treatments —prior impulse controlling activity, consumption of a sugared drink, and consumption of a sugar-free drink — on intertemporal financial decisions. Contrary to those models, prior exertion of impulse control increases financial patience. Sugared drink consumption also increases patience, but so does sugar-free drink consumption, raising doubts about blood glucose as a key willpower resource. To better understand these results, we estimate treatment effects on three structurally-estimated utility parameters for each subject. All three treatments have robust effects on utility curvature, and smaller effects on present-bias. These two parameters move together, though they are largely unaffected by the treatments among subjects with very high cognitive ability. We argue that these patterns are more consistent with a scenario where the treatments reduced subjects