According to the New Yorker:

As with any such upheaval, there’s a history behind it. Several weeks ago, I’m told, Abramson discovered that her pay and her pension benefits as both executive editor and, before that, as managing editor were considerably less than the pay and pension benefits of Bill Keller, the male editor whom she replaced in both jobs. “She confronted the top brass,” one close associate said, and this may have fed into the management’s narrative that she was “pushy,” a characterization that, for many, has an inescapably gendered aspect. Sulzberger is known to believe that the Times, as a financially beleaguered newspaper, needed to retreat on some of its generous pay and pension benefits; Abramson, who spent much of her career at the Wall Street Journal, had been at the Times for far fewer years than Keller, which accounted for some of the pension disparity. Eileen Murphy, a spokeswoman for the Times, said that Jill Abramson’s total compensation as executive editor “was directly comparable to Bill Keller’s”—though it was not actually the same. I was also told by another friend of Abramson’s that the pay gap with Keller was only closed after she complained. But, to women at an institution that was once sued by its female employees for discriminatory practices, the question brings up ugly memories. Whether Abramson was right or wrong, both sides were left unhappy. A third associate told me, “She found out that a former deputy managing editor”—a man—“made more money than she did” while she was managing editor. “She had a lawyer make polite inquiries about the pay and pension disparities, which set them off.”