I did a back of the envelope calc on the volcano thing. (realclimate.org)
I agree that I think MacKay would have been better to have done calcs for AVERAGE person — that is what I did when I repeated for NZ. (realclimate.org)
I did the same calc using 1.8 % inflation and get approx 4 times faster wage growth for (roughly) the top 20 %. (jaredbernsteinblog.com)