You seem to have missed that the thrust of the article could more be about overpaid CEO's than it is about underpaid workers.
Only one mentions workers pay:
> setting corporate tax rates higher for firms that have higher ratios of CEO-to-worker compensation
Even that doesn't seem like a good incentive to pay workers more.
It's also not clear how the IRS is going to evaluate CEO pay -> yearly tax rate when this study uses 'realized gains' which often happen well after the fact, since CEOs are paid with stock/equity. The study mentions almost all of the growth has been via the % of stocks CEOs now get, not their actual salary.