I believe that 8% is not merely an assumption, but comes from the paper he references here: http://marginalrevolution.com/marginalrevolution/2013/04/trade-vs-t

I believe that 8% is not merely an assumption, but comes from the paper he references here: http://marginalrevolution.com/marginalrevolution/2013/04/trade-vs-technology-in-terms-of-their-labor-market-effects.html http://marginalrevolution.com/marginalrevolution/2013/04/tra...