I’m currently reading Scarcity by by Sendhil Mullainathan and Eldar Shafir. At this stage, I’m inclined to sympathise with the unnamed colleague who commented “There’s already a science of scarcity. It’s called economics”. So far, it’s mostly straightforward applications of the observation that time and attention are scarce resources, combined with some fairly familiar observations from behavioral econ on how people fail to optimise either the first-order problems of allocating a tight budget or the second order problem of allocating time and attention to the first-order problem (my terms here, not theirs). However, I’m only part way through, and the authors promise to show how their approach differs from the way in which economists would normally think about this kind of problem.
This post is about a specific and well known observation cited by Mullainathan and Shafir. Faced with paying $100 for an item that could be had elsewhere for $50, most people are willing to put in a fair bit of effort (say, driving for an hour) to get the lower price.[^1] On the other hand if the item costs $1050 and could be had for $1000, people with reasonably high incomes mostly pay up, instead of driving to the other store. This is obviously inconsistent with standard opportunity cost.
[click to continue…]
