PwC will make its internal diversity findings public this week, having conducted the audits privately for the past two years.
Bagley told HR magazine that although there are some "shocks" when drilling down into gender pay differences for the first time, the exercise is useful for having conversations going forward.
"It's right to be having grown-up and frank conversations about the findings rather than being sensationalist," she said. "I've noticed that if someone wants to move someone from A to B and I say it's not entirely fair, they will listen to me now."
Bagley added that it can be complex to analyse the cause of any disparity in levels of pay.
"When you drill down you realise it's really complicated," she said. "When I took it to the board their reaction was 'well there shouldn't be a pay gap', which is a good sign. But this helps us all to understand what things we can do quickly and what things we're going to have to be patient about."
Putting the data into the public domain is also an important driver of change, according to Bagley. And she hopes PwC's example can encourage other companies to do the same.
"I have definitely found that when I do this publicly it is easier to focus people's attention when trying to get them to do things differently," she explained. "It's about holding ourselves to account. If we said we were going to do something we need to explain why we haven't done it."
