The issue with low pay and no benefits for adjunct professors has been around for a while now. Here is a new take on it from Slate Magazine looking at the oft used phrase “do what you love”. Money quote:

If DWYL denigrates or makes dangerously invisible vast swaths of labor that allow many of us to live in comfort and to do what we love, it has also caused great damage to the professions it portends to celebrate. Nowhere has the DWYL mantra been more devastating to its adherents than in academia. The average Ph.D. student of the mid-2000s forwent the easy money of finance and law (now slightly less easy) to live on a meager stipend in order to pursue his passion for Norse mythology or the history of Afro-Cuban music.
The reward for answering this higher calling is an academic employment marketplace in which about 41 percent of American faculty are adjunct professors—contract instructors who usually receive low pay, no benefits, no office, no job security, and no long-term stake in the schools where they work.

The problem is how to fix. Adjuncts are typically hired to teach sections filled with students but no available tenure-line instructional faculty member. This happens when faculty members are on sabbatical, or when they “buy out” of their course load from research grants (remember at US research universities, a faculty member typically splits their work between research, teaching and service). In theory the “buy down” from the grant should be sufficient for a living wage for the adjunct but as a matter of fact, rarely is that functionally the case (i.e. the adjunct is paid much less than the amount of the buy down).

Why?

Because the buy-down dollars are just too tempting for budgeteers….and because the market supports the low wages paid. With the advent of adjunct unionization, this may perhaps change.