Is there any empirical evidence to support any of these theories?
I doubt that there is data which thoroughly decouples the set of possible explanations (some of which you listed in your question). Many of these factors are so interrelated that attempting to decouple them in order to identify "the one root-cause" seems futile.
This circular dynamic illustrates some of these interrelations:
Technology has undeniably boosted workers' productivity and
contributed to globalization.
That creates an oversupply of goods and services, which translates to
oversupply in the labor market.
Both globalization and labor oversupply drive wages down in the U.S. (the weakening of U.S. labor unions is just another facet of oversupply and the ability to "consume" labor from overseas).
And these circumstances of unemployment foster fiercer competition among labor suppliers, which leads to further specialization and technological improvements.
Similar chains of reasoning can be developed if instead of technology one takes globalization or a fiscal/financial cojuncture as starting point. Either way, economic agents will seek to maximize profits, which in an open economy can only be attained by competition and innovation. That inevitably leads to lower wages and higher productivity, respectively.
An economist's efforts to solve this chicken-and-egg dilemma would be uninteresting, more so where other real and emerging problems are not even marginally captured in the aforementioned circular dynamics.
Although there has been so much outcry about wage stagnation in the U.S. (and other countries), no one can reasonably refute that even with today's "stagnated wages" people in these economies have access to many more goods and services than with the growing wages in the first decades following World War II.