Calling Bullshit: The Art of Skepticism in a Data-Driven World

by Carl T. Bergstrom

Marilyn Strathern rephrased it clearly and concisely: When a measure becomes a target, it ceases to be a good measure. In other words, if sufficient rewards are attached to some measure, people will find ways to increase their scores one way or another, and in doing so will undercut the value of the measure for assessing what it was originally designed to assess. We see this in any number of domains. In the sciences, the use of citation metrics to measure journal quality has led editors to game the system. Some pressure authors to include citations to papers in the same journal. Some publish an excess of articles in January, when they have the most time to be cited during the year. Others publish annual summary papers that cite many of the articles published within a year; yet others shift their focus to disciplines or types of articles that tend to attract more citations. All of these perverse behaviors undermine the mission of the journals and the effectiveness of citation measures as indicators of quality. When the manager of an auto dealership provides bonuses to salespeople for hitting certain volume targets, the sales force will have incentives to offer larger discounts to their customers, in order to make the sale quickly. If salespeople were trying to maximize profits in making each sale, one might be able to use the number of cars sold to approximate how much money each salesperson brings in. But once the number of cars sold becomes a target, salespeople alter the...