Most effective female CEO - Indra Nooyi

The Iron Woman of PepsiCo

"She is tough and smart, but she is also quite charismatic, and a born leader. And she is trying to do something really hard but really important - turn Pepsi into a company less dependent on its core soda business, and transition it to a company that makes food and drinks that are healthier," said the author of "Good Guys and Bad Buys", a collection of Nocera's writings about the heroes and villains of the US corporate world.

Asked if there is something different about Nooyi in comparison to an effective male CEO, Nocera replied in the negative.

"Good executives lead by example, by persuasion, by being able to explain why they are taking the course they are taking. People need to see that they are comfortable in their own skin, that they are not defensive, that they are empathetic - but that in the end, they can make the tough decisions. Jeff Immelt (GE chairman), in my opinion, has those qualities - and so does Indra Nooyi."

Asked about the best female entrepreneur in America, Nocera named Oprah Winfrey and Anita Roddick, founder of the Body Shop.

But he rued the fact that Wall Street remains a very male-oriented place and women can have a hard time there.

"Most trading floors still have very few women, for instance, and there aren't many women investment bankers either. The women who get to the executive suite on Wall Street are notable because there are so few of them. And two of them - Zoe Cruz at Morgan Stanley and Erin Callan at Lehman - recently lost their positions in no small part because their bosses were trying to save their own skins," he said.