The effect cannot be quantified....but it is undoubtedly exerting an influence over the price of the goods in the world market. For a scholarly view of the incidence of taxation.....please see:
Stephen J. Entin, TAX INCIDENCE, TAX BURDEN, AND TAX SHIFTING:WHO REALLY PAYS THE TAX?, Institute for the Research of the Economics of Taxation, Policy Bulletin No. 88, September 10, 2004, at: ftp://ftp.iret.org/pub/BLTN-88.PDF
That is the problem it cannot be quantified.
You seem to have knowledge in this area and I have not paid much attention are there other payroll/SS type taxes in Europe other than VAT?
Thanks for the link to the paper. Since it is 55 pages I will have to wait for more time to give it proper study.