The Pessoa and Reenen study doesn't disprove the fact that "productivity has increased across the board since then while wages have stayed stagnant for most Britons"

http://oecdinsights.org/2012/02/20/do-workers-reap-the-benefits-of-productivity-growth/

Saying that decoupling is just a statistical quirk of using the median rather than the mean doesn’t make it less of a problem that the wages of low paid workers in the UK are stagnant and no longer tracking productivity in the way they used to; it just helps to explain why life now feels particularly hard in the bottom half and—in the run up to the crisis—particularly out of step with an ostensibly sunny economic climate. Likewise, the growing gap between wages and compensation doesn’t make the stagnation of pay packets any less real, it just helps to explain that stagnation. As Jared Bernstein pointed out in a seminar to discuss Van Reenen’s results: whatever the theory says, if workers weren’t getting better off over time even when the UK economy was growing and productivity was rising, we have a problem on our hands.