In the American system, companies pay more of their profits, but must also spend lower money on wages to give its employees the same net income. Also, with lower social taxes (1.45% for Medicare and 6.045% for social security up to 6,045 USD), it fosters giving many jobs, because each individual costs the company little in this kind of taxes. Since the corporations income taxes are high at 35%, it promotes paying high wages to qualified employees because they will produce more for the company. If an american company raises the wage of an individual already making over 100,000 USD per annum by 100 dollars, it really only increases the cost to the company by 66.55 USD, because it saves money on taxes by having a lower income. I reached this number because after 100,000 USD per year, social security tax does not increase, as it is capped, and Medicare still costs 1.45%, so by lowering their income by paying 100 extra dollars, they save 35 Dollars in income taxes, and must pay 1.45 Dollars in Medicare tax. This system also promotes charitable contributions in order to gain tax breaks. A 100 Dollar increase on a salary of less than 100,000 USD, would cost the company 72.595 USD, because the Social Security tax would still be in effect, costing the company slightly more.
In the European system, lower income taxes mean that by increasing a salary by 100 Dollars, only cuts the companies taxes paid by 15 Dollars, much less than 35 Dollars for American companies. Also, this 15 Dollar "savings", is further cut into by the higher social taxes in Europe. This does not promote lowering income by increasing wages to save on taxes at all.
What about personal income taxes? We've see that in the US, it makes more sense for a corporation to raise wages than for a European one. On top of receiving a smaller gross paycheck in Europe, the European worker will be forced to pay larger amounts in taxes than the American worker, lowering his net income even further.
The result of this is that skilled workers generally leave Europe for America or for a country with a lower tax system where their work is better remunerated. This over a longer period of time, leaves Europe less highly skilled workers, and a larger percentage of unskilled, low paid workers. The effects can already be seen. The US has many more science nobel prizes than Europe, because American companies pay these great scientists better than European companies. Think of the best colleges in the world. The only European university that can compete with American ones is Cambridge. Again, this is because good Scientists and economists are paid better in the US, and therefore go there to work.
Socialism promotes mediocrity, whereas capitalism promotes excellence. The results can already be seen, but this contest just got started. The US is a very young country, and is slowly leeching the best thinkers out of Europe, seducing them with higher incomes. WE'll see how this turns out, but if it keeps going the way it has been, I don't see Europe toppling the US in technological breakthroughs any time soon.