Via email, Easterly tells me that their “distance from the equator” variable is “the ratio of degrees of latitude to 90 degrees.”  So what do their results imply about the net effect of immigration?  Let’s return to their key table, remembering that the published paper accidentally flipped the sign on “landlocked.”


So suppose you move the population of a landlocked equatorial country to a coastal country at 45 degrees latitude.  45 degrees latitude corresponds to a “distance from the equator” score of .5.  CEG’s results in column (3) therefore predict their log per-capita GDP will rise by .5*1.68 + .25*1.063+.646=1.75.  That almost exactly equals the effect of having ancestors with a tech score of 0 (the minimum) and ancestors with a tech score of 1 (the maximum).

The comparison for columns (1) and (2) is even more lopsided.  If you think CEG provides a clear-cut rationale for restricting Third World immigration, you’re suffering from confirmation bias.