How bad is incoherence?

How Bad Is Incoherence?

Rationality is often defined in terms of coherence, assuming that a single syntactical rule such as consistency, transitivity, or Bayes’ rule suffices to evaluate behavior. Many normative claims made in psychological research follow this assumption. We argue that coherence-based norms are of limited value for evaluating behavior as rational. Specifically, we maintain that (a) there is little ev...

How bad is fructose?

This issue of the Journal contains another disturbing article on the biology of fructose (1). Why is fructose of concern? First, it is sweeter than either glucose or sucrose. In fruit, it serves as a marker for foods that are nutritionally rich. However, in soft drinks and other “sweets,” fructose serves to reward sweet taste that provides “calories,” often without much else in the way of nutri...

How Bad Is Selfish Voting?

It is well known that strategic behavior in elections is essentially unavoidable; we therefore ask: how bad can the rational outcome be? We answer this question via the notion of the price of anarchy, using the scores of alternatives as a proxy for their quality and bounding the ratio between the score of the optimal alternative and the score of the winning alternative in Nash equilibrium. Spec...

How bad is selfish routing in practice?

Routing games are one of the most successful domains of application of game theory. It is well understood that simple dynamics converge to equilibria, whose performance is nearly optimal regardless of the size of the network or the number of agents. These strong theoretical assertions prompt a natural question: How well do these pen-and-paper calculations agree with the reality of everyday traf...

How Bad Is the Brazilian Crisis?