I found an old but fascinating article on procrastination by Ainslie, available at his website here for those interested. Ainslie is a psychiatrist and has a background in behavioural psychology as well as a wide variety of other disciplines. He has published extensively on willpower and is a central figure in what is called picoeconomics. In this article Ainslie uses his models of hyperbolic discounting and intertemporal bargaining to create a model of procrastination – a temporary preference for a small, sooner reward, than a large, later reward.