It&#x27;s more accurate to say that the cost of shipping something across an ocean dropped so low because of containerisation that virtually any disparity in the cost of input factors (not just labour - energy, land, etc as well) is worth exploiting via geographical arbitrage.<p>Even without unions, the cost of living disparity is such that in many cases if American firms matched the wages of even relatively well paid Chinese workers they simply couldn&#x27;t survive on them in the US.