In Jay Newton-Small’s new book “Broad Influence: How Women are Changing the Way America Works” she looks at the way women’s roles in the public and private sector are transforming. Newton-Small argues that once women reach “critical mass,” or 20-30 percent, in a group, change starts to happen for the better.

Here’s an excerpt from Lizzie’s conversation with Newton-Small:

On critical mass:

Well the idea for the book came about two years ago when I was covering…the Senate. The women of the Senate had reached 20 percent, and it was the first time they were at 20 percent. They really, really batted above their weight. They ended up producing 75 percent of the major legislation that passed the Senate that session. …So I started researching this idea but it turns out it’s pretty widespread.

Public vs Private Sector:

The public sector is reaching critical mass in all three branches of the government and that’s striking because ten years ago it was the private sector that lead the public sector, but they haven’t made any progress since.

One reason is that….

There’s just an easier on-ramping in the public sector than there is the private sector. If you look at New Hampshire for example…it has a lower house of more than 400 members representing 3 million people. It’s a very small leap to go from running for school board to state legislature. It’s a part time job…women who have children can easily do it. As their kids get older they can spend more time there, they can run for higher office, the can start chairing committees…at one point in the last five years the entire delegation was women. That shows you how women in the public sector have a much easier on ramping path than women in the private sector, which tends to be all or nothing. You’re working full-time or not at all, and there’s not a lot of part-time prospects.

On her mom and the meaning of critical mass:

My mom had such a hard time at work, she really faced so much harassment, and she was miserable. I often saw her crying at the kitchen table as a child. I guess I’d like her to see that, as along as she was in her career, I have a whole class of friends, of colleagues, who are women, who are with me. So when I face something akin to what she faced, which is actually rarer and rarer these days, I have a whole group of people around me to support me and I’m not alone. That to me is the power of critical mass; that we don’t feel like the odd person out that we have each other…and it helps us succeed and get further in our careers, and I wish that she’d been able to see that.