I credit my bosses at a charter school I worked at with sparking my interest in unions. I’d always been progressive and I’d long since decided socialism was the answer, but I never gave much thought to unions until I experienced firsthand why workers need them.

My first day at work began with a meeting of all employees, new and old. As we went around the room introducing ourselves, I began to feel a strange sense of unease. My coworkers and I stated our names, the subject we would be teaching and also how long we’d worked at the school. Teacher after teacher said, “I’ve been here one month” or, “This is my first day.” If I had been starting a new job at a fast food restaurant, I might not have been surprised by such a high turnover rate. But in a high school it suggested serious problems.

Like most charter schoolteachers, we were “at-will” employees. We could be terminated at any time, for any reason. And our employers made this painfully clear. Firings were frequent, and seemingly random. Administrators would insist that teachers were adequately counseled and that firings were for just cause, but we knew that progressive discipline and due process were lies as untrue as the lies told to prospective parents touring the school. An atmosphere of fear and paranoia prevailed.

An American Federation of Teachers report found that in most states charter schools rely predominantly on inexperienced, uncertified teachers. Our school was no exception. Lack of experience and lack of professional preparation made many of us either unaware of or too timid to challenge the many unsound educational practices required of us, practices that robbed our students of a true learning experience.

With so many inexperienced, uncertified, at-will employees, charter schools frequently exploit their workers with low pay. Charter school teachers, on average, earn much less than their public school counterparts. The same AFT study reports salary gaps of $9,000 to $15,000 in four of the states studied.

These injustices and many more lead to a comparatively high staff turnover rate in charter schools. One year my colleagues and I estimated the teacher turnover rate at 80 percent, including firings and resignations. Bad for teachers, bad for students.

Charter schoolteachers, like all workers, need union representation. Not only will this improve the working conditions of teachers, but a unionized workforce would begin to bring some of the accountability that charter school proponents have long touted, but that numerous studies have found absent from the charter school movement.

Deb Wilmer is a public education activist in Arizona.