At the same time, non-purely technological hypotheses for rising mean-median inequality include the race between education and technology (Goldin and Katz 2007), declining unionisation (Freeman et al. 2016), globalisation (Autor et al. 2013), immigration (Borjas 2003), and the ‘superstar effect’ (Rosen 1981, Gabaix et al. 2016). Non-technological hypotheses for the falling labour share include labour market institutions (Levy and Temin 2007, Mishel and Bivens 2015), market structure and monopoly power (Autor et al. 2017, Barkai 2017), capital accumulation (Piketty 2014, Piketty and Zucman 2014), and the productivity slowdown itself (Grossman et al. 2017).
All of the non-technological reasons, to me, boil down to globalization.
I'd love to see the productivity-wage divergence chart in China and other developing countries. I wouldn't be surprised if the divergence is inverted in those places that have seen unprecedented wage growth over the last forty years.
I guess what I'm saying is that I don't think productivity and wages have diverged as much as people think, it's just that a national analysis is insufficient in a global labor market.