The theory that hot countries are intrinsically poor, though contradicted by the recent rapid economic advance of countries such as Singapore, Malaysia, and Botswana, is still forcefully advocated by some, such as the economist Jeffrey Sachs. The modern version of this view emphasizes not the direct effects of climate on work effort or thought processes, but two additional arguments: first, that tropical diseases, particularly malaria, have very adverse consequences for health and therefore labor productivity; and second, that tropical soils do not allow for productive agriculture.
