$7.25 an hour. Imagine feeding a family on that. That’s the magic trick low-wage working women – who make up 2/3 of those earning minimum wages or less – have to perform on a daily basis.

As Kate Gallagher Robbins pointed out yesterday, an hourly wage of $7.25 leaves a person working full time year round with just $14,500—or $3000 below the poverty line for a mom with two kids.

But where does that $7.25 an hour leave workers who can’t get a full-time job? Involuntary part-time work is a huge problem for low-wage workers in today’s labor market. BLS data from 2011 (PDF) show that 8.5 million people were in part-time work for economic reasons like slack work, only being able to find a part-time job or seasonal work.

Instead of multiplying $7.25 by 40 hours a week, for these workers the math looks more like $7.25 x 20 or 25 hours (and in many cases, even fewer hours). In other words, workers earning minimum wages in involuntary part-time jobs are hit much harder by the painfully low minimum wage.

And, unfortunately, the number of workers working in part-time jobs involuntarily has increased dramatically since the recession, as this chart from EPI powerfully illustrates:

The number of workers working in part-time jobs involuntarily has increased dramatically since the recession

from Economic Policy Institute

Involuntary part-time work is a major problem for women who are heavily concentrated in the industries that employ the greatest numbers of workers in involuntary part-time jobs, like wholesale and retail trade, education and health services and leisure and hospitality (PDF).

These are also the same industries that employ huge numbers of workers in low-wage jobs (PDF).

Now to go from bad to worse: For many of these workers schedules are often assigned at the last minute and hours fluctuate radically from week to week and month to month (PDF). Some workers are scheduled to work and sent home without pay when business is slow (sometimes in violation of reporting time pay laws in the states that have those).

According to Carrie Gleason, director of the Retail Action Project, it’s gotten to the point where hours are the new bonus.”

Not only do these schedule fluctuations wreak havoc on the lives of hardworking women and men, they wreak havoc on their incomes – making it impossible to know in any given month what income they can count on – and whether it will cover groceries, rent, child care and other expenses.

So, let’s look at the facts:

  • The purchasing power of the minimum wage has declined dramatically – more than 30% from what it was in 1968 (PDF).
  • The number of employees working in low-wage involuntary part-time jobs has skyrocketed.

Low-wage working families have always had to do more with less, but the one-two punch of low wages and involuntary part-time work has pushed too many American families past the breaking point.

That’s one more good reason why the National Women’s Law Center supports the Rebuild America Act which would raise the minimum wage to $9.80 over three years, and after that, index the minimum wage to inflation to maintain its value.