"...even the more refined recent studies show that lower-paid employees still had quite respectable success rates in arbitration, ranging from about 21% to almost 40%. That compares very favorably with the 23% win rate of union-represented employees that I found in one of the oldest and most respected labor arbitration systems in the country."
The author is comparing arbitration and arbitration, not arbitration and courts. Is there any place in the article where he addresses the research in the other paper, or is he just saying "it's not that bad."
Also, I'm not sure what the existence of insurance against employee claims has to do with the claim that wages would be lowered? Do you have any evidence for a connection other than inductive reasoning?