The study claims that higher temperatures suppress economic growth in poor countries. The claim falls apart when you look at their definitions. The authors study the period 1961-2003 and assign each country a binary designation as “poor” or “rich” based on whether their per capita gross domestic product was below or above the median for countries in 1960.

But some countries faced drastic changes in fortune at the time.

South Korea is “poor,” according to the authors. In reality, it was very poor in the early 1960s and then became very wealthy. When I simply reclassified South Korea as poor from 1961-76 and rich from 1977-2003, the study’s results nearly disappeared. When I allowed classifications of all countries to change when they moved either above or below median GDP per capita, the results disappeared completely. Any study with results that collapse after such a simple specification change shouldn’t be published in a peer-reviewed academic journal.

[They’re paying for the conclusion, not for scholarship. — Ed]