Despite a recent flurry of wage hike announcements from some big chains — and what you might have heard about a labor shortage driving up wages — the majority of workers at the nation’s largest companies still earn less than $15 an hour.

Why it matters: Since 2012, activists have fought to raise the federal minimum wage to $15, with only limited success. Inflation is eroding that number.

• Today's $15 is the equivalent of $11.97 a decade ago, according to this handy calculator. Put another way, today, you'd have to call it the Fight for $18.80.
• Someone working full time at $15 an hour (typically not even an option for these workers) will earn a little more than $30,000 a year — less if they need sick days, and many don't get that benefit.

What’s happening: According to a survey of 21,000 hourly workers at 66 U.S. companies released Tuesday, two-thirds of workers at some of the largest retail, fast-food and hospitality chains make less than $15.

• The ongoing survey was conducted by The Shift Project, an endeavor by sociologists at Harvard and the University of California, San Francisco and released with the progressive think tank, Economic Policy Institute.

By the numbers: While there's been a rise in pay lately, these workers are still struggling, said Kristen Harknett, who cofounded the survey.

• At 44 companies surveyed, the majority of workers earn less than $15 an hour.
• There's often a lot of variation. For example, at Walmart, 49% of workers earn more than $15, compared to 97% at Target.

Meanwhile, on top of the low hourly pay, many workers aren't getting enough hours assigned, Harknett said.

• "Best case scenario, workers are getting 35 hours but a lot of times they're getting 25 hours — not sufficient to make ends meet."