In response, the company has now issued a statement saying arguing that "discussion of pay inequality between Barra and her predecessor is premature and flawed," adding that she might get extra long-term compensation after the company's annual meeting. But it also put forward an implication that seems likely to accelerate the controversy: it cited Akerson's simultaneous service as chairman of the board and his "previous experience" in the statement's clarification of his earnings. Considering that Barra has worked at GM for more than 30 years and Akerson had no auto industry experience before becoming CEO, it's not immediately obvious what "previous experience" the PR people are talking about.

The answer lies in that other point GM's statement makes: that Barra serves solely as CEO. In fact, the downsizing of her position goes further than that — in addition to having to answer to self-described "activist chairman," Tim Solso, Barra also shares responsibilities with former chief financial officer Tim Ammann, who has been given the newly resurrected position of president. Objectively, Barra's job carries far less responsibility than Akerson's. So is that justification for lower pay, or just more evidence that GM's male-dominated executive corps has paternalistically elevated Barra as a token female figurehead?

Being well-versed in neither human resources practice nor gender studies theory, I'll leave the analysis of possible sexism to others. But having followed GM for some time, I see in this story traces of another fundamentally imbalanced power relationship that has long colored GM's history: what former vice chairman Bob Lutz termed "Car Guys vs. Bean Counters." Given this history, you have to consider another likely factor in Barra's role and pay: her total lack of finance experience.