Hartmann believes discrimination accounts for between 25 percent and 33 percent of the wage gap. Compensation specialist Gary Thornton, a principal in the HR management consulting firm Thornton & Associates, figures at least 10 percent to 15 percent does.
Whatever the breakout, there certainly are numerous studies that show discrimination -- however unconscious -- still exists. For instance:
A recent Cornell study found that female job applicants with children would be less likely to get hired, and if they do, would be paid a lower salary than other candidates, male and female. By contrast, male applicants with children would be offered a higher salary than non-fathers and other mothers.
A recent Carnegie Mellon study found that female job applicants who tried to negotiate a higher salary were less likely to be hired by male managers, while male applicants were not.
Then there's the phenomenon of wages going down when more women move into a field.
Take human resources, now a female-dominated profession. I asked Thornton if he thinks female human-resource managers today are paid as well as he and his male colleagues were 15 years ago. "Not at all," he said. He estimates that in inflation-adjusted terms they're paid about 20 percent less.
Why? "That's the million-dollar question," he said. "There are many things at play. But we still have a long way to go to change unintentional discrimination."
A few years back, the Massachusetts Institute of Technology found that its women scientists were routinely given less pay, space, funding and rewards than their male colleagues.
"Did anyone intentionally give them smaller offices and labs? Probably not. It's just one of those things (that) accumulate and add up to barriers and institutional discrimination," Hartmann said.
Even though discrimination may not be intentional, Hartmann said, companies should be intentional about regularly reviewing their compensation structures and promotion records to correct for patterns of discrimination.
But maybe there can never be absolute parity because often there are many non-discriminatory variables that cause a differential in pay. What determines someone's pay isn't just a title and job description, but also performance, tenure and market forces -- e.g., what it takes to get a desirable job candidate to accept a position.
