A mantra for artists everywhere — this “Get Paid” pennant by BT Livermore is, of course, for sale.

Yesterday Gawker reported that Girls creator Lena Dunham would not be paying the opening acts on the tour for her book Not That Kind of Girl. This was a galling financial revelation given that this is not a typical book tour—an author with a miniscule travel budget hoping to fill seats at a few bookstores—but a 12-city extravaganza where tickets to see the author and opening local performers were going for $38 a pop.

By the end of the day, Dunham had responded to the criticism with a pledge to pay the opening acts. “As an artist raised by artists, no one believes more than I do that creators should be fairly compensated for their work,” Dunham tweeted. “This feature of the tour was meant to showcase local talent and I could not be more excited about it. Some good points were raised and I’ve ensured that all local acts will be compensated for their time, their labor and their talents.”

While the opening acts will now be paid, this discussion raised the issue of how people frequently assume that artists don’t need to be paid for their work. A very similar thing happened in 2012, when performer Amanda Palmer defended her plan to pay musicians for her tour with “beer, hugs, merch, free tickets, and love” but not cash. Like the opening acts for Dunham’s current tour, Amanda Palmer’s musicians volunteered for the gig and, like Dunham, criticism promoted Palmer to eventually change course and pay the musicians. After all, they both had the money to pay artists—as Palmer explained, “We have the power to do it, and we’re going to do it.” The fact that both of these women who are artists themselves had the money to pay other performers but didn’t initially think it was necessary speaks to a troubling reality.

Why is it assumed that professional artists will work for free? It would be absurd to expect a computer programmer to build a database for free or to ask a plumber to repair your pipes for free, but when people are experts at writing, music, dance, and visual art, employers routinely expect to exchange nothing more than beer, hugs, or good vibes for their time and skills. New York advocacy group Working Artists and the Greater Economy (WAGE) surveyed artists in 2010 and found that 58 percent had at some point not been paid for exhibiting in NYC museums and other nonprofit institutions.

From WAGE’s report on New York artists’ income.

I think this lack of payment comes in part from a perception that artists are getting something out of the arrangement—that art is its own reward. It’s true that many artists love creating their work, but it’s not a joy that appears for free out of the ether. Becoming a professional artist takes lots of time and money. An extensive 2010 study on the finances of professional artists in Australia (tellingly titled “Do You Really Expect to Get Paid?”) revealed that cost of creating art: the average artist working in Australia invests more than $5,000 annually in their work.

Despite the significant financial investment that their career requires, the Australian artists are underpaid compared to people working in other fields. This definitely looks like a pattern that we see in the United States, too. Money isn’t the single motivating goal for many artists, but payment is necessary to allow them to keep working. You can’t survive on beer and hugs alone.

I think that underlying the trend of not paying artists is the perception that technical work—in traditionally male-dominated fields—is more worthy of payment than work that creates a better social environment. Similar to women who have demanded wages for housework and domestic workers who have organized to demand fair pay for their labor, many artists spend their personal time and money on work that makes people happier, healthier, and more socially connected. Or, as WAGE flashes in bright text to visitors on their site, “We demand payment for making the world more interesting.”

Many artists are generous in giving away their time and skills for free to support good causes and to entertain folks. But more than anyone, other artists should understand that paying an artist who is working onstage at their well-funded event isn’t a bonus or an afterthought, it’s essential support for someone whose work requires significant energy, time, and money.

Sarah Mirk is Bitch’s online editor. She clearly likes charts a lot.