Jill Abramson, former executive editor at the New York Times waves after speaking during commencement ceremonies for Wake Forest University. - 

You’ve probably been hearing the name “Jill Abramson” a lot lately.

The former New York Times Executive Editor’s firing last week has started a new conversation about an old problem in the corporate world: the fact that there are hardly any female CEOs.

“I don’t think this is primarily some kind of Oliver Stone-like conspiracy,” says  Nancy Koehn, a historian at the Harvard Business School. “I think it's primarily that the tributaries that feed into the river of talent haven’t -- until recently -- been replete with talented women. Not because they aren’t out there in droves -- they are -- but because [they have] only recently come into the kinds of management jobs which feed top leadership talent.”

Koehn says women traditionally haven’t worked as much in the direct roles like sales and research that lead to executive jobs. She says General Motors CEO Mary Barra is an example of what can happen when women buck that trend.

“[She] didn’t stay in HR. She didn’t stay in PR or Legal. Instead, [she] was moved around into Manufacturing and Research...She had a full plate of professional positions that made her a great candidate to run this huge auto company.”

Koehn says it won’t be long until stories like Barra’s aren’t a rarity.

“[This] kind of social change isn’t a line. It's a curve. It's slow to begin with, like the adoption of a new technology, and then it ratchets up. And it has all these spillover effects. Talented women mentor other women. They mentor other women. The curve gets very steep very quickly.”