Empirical explanation on divergence between productivity and wages since the 70s There is a well know graph, that shows a tight link between productivity and wages, until the 70s, and a break of the link since:


There's a lot of possible explanations for this, I keep hearing more of them:


Tax cuts to corporations, that changed the profits distribution 
detachment from the gold standard 
Rise in global trade and the consequential drop in the US industry power in the economy 
The loss of power of labour unions


There is a good article here

I actually thought of a possible reason myself: the decrease of competitiveness of the labor market as a result of mergers and acquisitions or the drop in power of labour unions, as said

High wages in today's hi tech industry can support this explanation in the opposite way

Is there any empirical evidence to support any of these theories?
This is sort of my field, tough I focus more on education. One explanation that seems to fit the data is that the american labor market now is incorporating benefits and variable pay, so wages should decouple from productivity if total compensation doesn't - and voi lá, that's whats happening.


  One reason, perhaps, is that the character of the productivity acceleration
  changed circa 2000. Prior to that date, studies have suggested
  that the more important effect was an increasing ratio of capital
  to labor (capital deepening) as businesses substituted relatively
  less expensive information technology and communication equipment
  for labor. Since 2000, some studies suggest that the more
  important factor has been a re-engineering of business practices,
  which has increased the “skill bias” in the labor market, that is,
  the premium paid for higher levels of technical, professional, and
  managerial education and experience. For employers, variable pay
  solves, in part, the problem of monitoring the performance of such
  workers: Unlike traditional factory and retail service workers,
  whose hours at work are relatively easily monitored, many skilled
  professionals work at varied locations and times of day. Finally,
  increasing reliance on variable pay also perhaps is a type of risksharing
  arrangement between businesses and workers. If the recent
  productivity trend slows, reducing or curtailing variable pay may
  be less offensive to professional workers than reductions in base
  salaries.