I suppose I should have been more verbose above. Basically, I don't want to say that davidkatz's and yours notes about the possible errors and biases of the study are unfounded. IMO, every study or report should be approached with these precautions in mind, if simply because all data has to be interpretted at some point which makes it subjective. But the main point I was trying to get across is that a study of this size conducted by someone of academic authority should not be simply waved off as a piece of bull b/c of possible errors, which was the impression that davidkatz's post made on me.