I haven't read Gladwell's book, but does it compare Korean and USA PDI and disaster rates, or disaster rates from a large number of countries?<p>If Gladwell has looked at a few more countries (and perhaps even ploted PDI against crashes) then he's done a much better job than Greenspun's comparison of "Foriegn" and "US" pilots.<p>If not, then the ball would be in Gladwell's court (so to speak).<p>It's obvious that Greenspun knows US air safety better than Gladwell though.