The gender wage gap is a hot topic. So hot that President Obama’s first act when he took office was signing the Lilly Ledbetter Act, which give the victims of pay discrimination more time to file charges against their employers. It even came up during the presidential campaign last year and was pointedly raised during one of the debates.

With all of this attention and even some legislation, you might think that we’re making progress toward closing the gap between men and women’s earnings. You’d be wrong. In fact, a new report from the Institute for Women’s Policy Research out today shows that the gap between median annual earnings for men and women working full time was lower in 2011 than in 2010 – and in fact equal to the gap as it stood in 2009. Median weekly earnings for full-time workers saw a gap of 80.9 percent in 2012, declining more than a whole percentage point since the year before. (Keep in mind all you gender gap naysayers: this is for full-time employees. Factoring in women’s “choices” to go part-time or take time off from their careers would make the gap even larger.)

What’s particularly strange about this is that the wage gap typically narrows during a recession, as Ariane Hegewisch of IWPR told me. “This is because men are more likely to work in jobs with high bonus payments and overtime work; in a recession discretionary payments such as merit pay tend to go down,” and men are the primary recipients of these lavish rewards.

What’s worse, though, is that this latest speed bump is dwarfed by the slowdown in progress since the 1990s, as can be seen in the graph above. As the report notes, “Since 2001 the annual gender earnings gap narrowed by only about one percentage point. In the previous decade, from 1991 to 2000, it closed by almost four, and in the decade prior to that, 1981 to 1990, by over ten percentage points.” Where we were making solid progress toward true gender parity in pay, recent decades have seen it trickle to a slow crawl.

So what’s going on here? No one is quite sure yet why the recent slowdown has occurred. Hegewisch posited that men’s bonuses may be returning to normal, increasing the gap. Another important factor is likely that the public sector has been shedding so many jobs, a place where women hold a large share of employment. The jobs there are also higher paying and tend to employ more educated women – so as they lost those jobs, they brought the average compensation for female workers down with them.

The longer-term path of stagnation that we’ve been on for the past two decades is caused by two factors: women’s earnings going up and men’s earnings stagnating or going down. Women saw a huge boost from doors opening for higher-level jobs thanks to Title IX and more equal access to education and Title VII. Mothers also entered and stayed in jobs more rapidly during that time. At the same time, men’s real wages suffered from the decline in manufacturing and anti-union policies. “Women’s earnings tended to be so low that the only way was up,” Hegewisch summed up.

It’s a complex problem, and so far we’ve tried to address it with minimal solutions. But our efforts aren’t paying off. Women are backsliding.