Goodhart’s Law and Argentinian hamburgers
Goodhart’s Law says Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.
The Big Mac Index has been used to compare prices across countries, as we have noted before.
Brazil Argentina currently has very high prices due to a combination of inflation and a strong economy, and this shows up glaringly in the Big Mac Index.
Tyler Cowen reports (translating a Spanish original) that the
Brazilian Argentinian government has persuaded McDonalds to lower the price of the Big Mac (relative to other McDonalds items, and relative to competing hamburgers), so that Brazil’s Big Mac Index becomes more competitive.
Updated: I actually do know that Argentina and Brazil are different countries, and that Brazil doesn’t speak Spanish.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. See all posts by Thomas Lumley »