There has been a lot of talk lately about whether Silicon Valley discriminates against women. In honor of Equal Pay Day, a depressing holiday, for sure, let's take a closer look at just how well women in the tech industry are doing.

Here's the headline: There is a smaller gender pay gap for tech jobs. But that's not the entire story.

In a 2014 analysis, Claudia Goldin, a Harvard University labor economist, found that many tech jobs have among the smallest gender wage gaps of all occupations. Female engineering managers, for instance, make about the same amount as their male counterparts when you control for other factors such as age and education, as the New York Times noted last year. Female computer programmers and computer scientists made about 90 percent of what men in the same occupation made, she found. That's a lot better than female financial specialists, who make just 66 percent of their male peers' salaries — or physicians and surgeons, who make 71 percent.

There's a pretty clear reason that women in these type of tech positions are more likely to earn as much as their male counterparts, according to Goldin. Tech jobs "seem to have less time pressure," she said. Women tend to be paid more equally in jobs that allow for a more flexible schedule, and coding, for instance, can be done almost anywhere at almost any time.

But the good news about tech jobs' narrow wage gap doesn't tell the entire story about where women stand in the tech industry.

A recent survey by Dice, a long-running career site for technology and engineering professionals, found that there is another type of gap.

Men, Dice found, were much more likely to have a job title that paid better: The average salaries of the top 10 tech positions held by men in 2014 ranged from $92,245 to $127,750, but the top 10 tech jobs held by women had a much lower range — between $43,068 and $98,328.

So Dice's data shows that something else might be going on here: a "position gap" that appears to most accurately explain the difference between men and women in the tech sector.

Charts from a recent report from the American Association of University Women (AAUW) on women in STEM fields can help illustrate this point. First, let's look at the pay gap. Like in Goldin's analysis, they show that tech occupations have narrower pay gap compared with other jobs:

The chart shows, for example, that software developers are among the most highly paid in the tech industry and that there is a relatively small pay gap between men and women in the field. Programmers, too, are paid fairly well — especially in comparison with, say, computer support specialists.

But now take a look at this chart, which shows the rates of women in select tech jobs:

Women make up just  20 percent of software developers and 24 percent of programmers.

But they are 28 percent of computer support specialists, which has a small pay gap but pays tens of thousands of dollars less per year on average.

Men and women in the same occupations often have little to no wage gap early in their careers, according to Goldin. But a 2013 AAUW report noted that one year after college graduation, female computer and information science majors who worked full time made just 77 percent of the annual salaries of their male peers. This may indicate that female computer science graduates are ending up in those lower-paying occupations, are not moving up the ladder as quickly as their male peers, or have ended up working outside of technical roles altogether.

And it also tracks with what we know about women at big tech companies, such as Google and Facebook. Diversity reports suggest that women are particularly underrepresented in tech-specific jobs and leadership, where compensation tends to be higher.

"It is definitely the case that the wage gap is less in tech," said Elizabeth Ames, a vice president at the Anita Borg Institute. "But what doesn't show up there is women not necessarily being promoted up the ladder — a woman might be doing a job where she's paid relatively equal to her peers, but there are a lot of men with similar qualifications who are at levels above her."

Twitter is facing a lawsuit alleging that this sort of thing happens at the company. The suit claims that promotions are decided by a mysterious "shoulder tap" system where open positions aren't publicly posted.

Some academics even think that "ingroup favoritism" — basically the idea that people tend to like people who are like them — is responsible for most modern types of discrimination. That's why the position gap is so important: The lack of women at the top means it's even harder for young women to climb the ladder.

This is true even if those making hiring and firing decisions aren't trying to discriminate, which makes it even harder to fight.

"It's true that explicit bias has diminished overtime, but what we're struggling with now is implicit bias — many people just subconsciously think men are better at some of these types of work," said Catherine Hill, vice president for research at AAUW.