I agree with this: employees are at a huge information disadvantage. However, I think a better (& admittedly more radical) solution to this problem would be to force employers to publicly post anonymized salaries by job title. That way prospective and current employees know exactly how much they ought to be paid. It makes salary negotiation almost trivial.

Preventing employers from asking about previous salary does not prevent them from discriminating against women, which is the intention of the MA law. I can definitely see how this law might hasten a transition away from an era where salary was unfairly pegged to gender - but only to the degree that employers aren't still just blatantly discriminating by gender.