Norm Matloff at UC Davis has blogged about this for a decade. A sampling of one paper has several references about the bias toward much younger and cheaper H1-B candidates in academia and professional workforce. He also argues diversity is better.
Thanks for the link. It looks like he wrote for U of M Journal of Law Reform on this topic: http://heather.cs.ucdavis.edu/Mich.pdf. Until I read through it and cross check his sources I can't judge the validity of course, but after reading over the first two pages his arguments seem compelling.
https://normsaysno.wordpress.com/2016/12/10/reforming-h-1b-a...