The reason tenure exists in K-12 education is because teachers—and especially their union leaders—saw a model in higher education for lifetime job security that they could carry over to their own schools. Today, however, tenure is fading in post-secondary education. Will the same thing occur in K-12 schools? Let us earnestly hope so, for the negatives of tenure have come to far outweigh its positives.

In almost every private conversation I’ve recently had with a college dean or university provost, they’ve confided that their institutions are phasing out tenure. Sometimes the shift is dramatic, particularly when spurred by lawmakers, such as the changes underway at the University of Wisconsin in the aftermath of Governor Scott Walker’s 2015 legislative success. Tenure-ending bills were introduced this winter in the Iowa and Missouri legislatures and, while they didn’t make it into law this time around, kindred efforts are bound to continue in many state capitals.

Often, though, the impulse to contain tenure on campus arises within the institution’s own leadership and takes the form of hiring fewer tenured or tenure-track faculty, instead filling classroom vacancies with what the American Association of University Professors terms “contingent” faculty, i.e., non-tenured instructors, clinical professors, and adjunct professors. In many medical schools, tenure has been severed from pay, so that professors may nominally win tenure but that status carries no right to a salary unless they raise the money themselves from grants or patents. This sort of change is underway across much of U.S. postsecondary education. Whereas tenured and tenure-track faculty comprised 56 percent of the instructional staff in American higher education in the mid-1970s (excluding graduate students who teach undergrads), by 2011 that figure had shrunk to 29 percent. In other words, seven out of 10 college instructors were “contingent” employees—and almost three-quarters of those were part-timers.

The data since 2011 are scanty, but there’s reason to believe these trend lines have continued and perhaps steepened—if for no other reason than pressures to hold down costs and, sometimes, to retrieve an institution’s capacity to innovate.

University tuitions are out of control, state subsidies are withering, and, although provosts and deans must often contend with their own unions as well as with tradition and current contracts, they still have a fair amount of flexibility in whom and how they hire, promote, and retain. Shifting from tenured to term appointments can save a lot. As Megan McArdle wrote in The Atlantic several years ago, “Hiring someone on a five-year contract at $80,000 is much less expensive than hiring them on a 40-year contract at $65,000. One is a liability of perhaps $350,000; the other, of millions.”

In the K–12 world, however, tenure remains the norm for public school teachers in the district sector, vouchsafed in most places by state law and politics, as well as local contracts, even in so-called “right to work” states. It may be achieved after as few as three years of classroom experience and be based on nothing more than a few “satisfactory” evaluations bestowed by a novice teacher’s supervisor during that period.

Unfortunately, we have ample evidence that such evaluations are nearly always at least “satisfactory” if not “outstanding.” Although many states and districts made worthy changes to their teacher-evaluation practices in response to now-spent Race to the Top dollars, the pushback against those changes was intense, the methodology usually had flaws (especially when linking student learning to teacher performance), and many districts have softened or abandoned this pursuit. Which means, of course, that the principals of district-operated public schools continue to have little ability to select, deploy, promote, retain and compensate the instructors they think do the best job for their students—much less to dismiss unsatisfactory teachers. Although a handful of school systems have installed elaborate “peer review” schemes to address the problem of tenured teachers who lose (or never really had) their mojo, these are cumbersome, costly, and confer little real management authority on school leaders.

It’s useful to distinguish two issues. The first is the complicated and politically fraught business of evaluating teachers, both new and veteran: how to do it, who should do it, what should the evaluation be based on, what should its consequences be, what politics surround it, etc.

The second issue is the question of tenure itself: should teachers, often by the age of 25, obtain guaranteed lifetime employment in a school system on the basis of a few years of satisfactory evaluations? For that matter, should anyone get lifetime tenure in any job? This question may legitimately be asked of civil servants, policemen, soldiers, and judges, as well as school and university faculty.

Personally—and speaking as a onetime tenured university professor who cheerfully gave it up for more rewarding pursuits—I’ve come to believe that only appellate judges deserve tenure (and it wouldn’t be hard to talk me into limiting that to the Supreme Court).

Teacher—and professor—tenure rests on three pillars: simple job security and longevity, really a form of guaranteed continuing employment (and often viewed as a fringe benefit that substitutes for more pay); protection against diverse forms of discrimination, favoritism, and capriciousness on the part of employers; and academic freedom, meaning in essence that instructors can almost never be fired on account of what they say or write.

The first of those is really just a matter of “terms of employment.” How valuable is job security to the employee—and to the employer? Would you rather earn $50,000 a year in a job that you know will continue indefinitely and does not depend on performance, or $75,000 in a job that is assured only for a several-year term and where renewal of the position hinges on how well you do at it? As we observe school teachers in major cities finding it hard to afford housing on their current salaries, we might reasonably suppose that many, given the option, would choose higher pay. And the districts that employ them would surely welcome back the budgetary flexibility and reduced long-term obligations that follow.

The second rationale for tenure—a safe harbor from discrimination and favoritism—deserves to be taken seriously. But the codification in constitutions and statutes of innumerable due process and anti-discrimination protections radically shrinks the rationale for inserting additional tenure provisions into employment contracts for this reason.

Academic freedom is a serious matter, too—but it’s significantly protected by the First Amendment and, for me at least, carries less oomph at a time when too many professors and teachers, especially in the humanities and social sciences, are indoctrinating their students and shielding them from unpleasant thoughts rather than teaching them to weigh evidence, consider multiple interpretations, wrestle with controversy, and seek truth and beauty as best they can. It’s also important to note that sundry court decisions have limited the extent of “free speech” in schoolrooms. Besides, just how much difference does “academic freedom” make to a fourth-grade teacher anyway?

It’s no secret that the HR practices of private and charter schools—neither of which typically practices tenure—work far better than those of district schools from the standpoint of both principals and students. (A forthcoming Fordham Institute study also shows that far fewer of their teachers are chronically absent.) That’s because a school’s leaders can generally hire and deploy the instructors they deem best suited to their pupils, and they’re not obligated to retain any teachers who don’t do a satisfactory job. They can be nimble in regrouping, re-staffing, and redirecting their schools—and everyone who is employed there knows that’s the way it works. Nobody has a right to continued employment untethered to performance and the school’s needs. The employer has the authority to alter the shape, nature, and size of the organization, to redeploy human resources, to substitute capital for labor, to replace elbow grease and sitzfleisch with technology, and to hire and fire according to shifting pupil needs and organizational priorities.

That’s the direction in which higher education is gradually heading, mostly because tenure is too rigid and costly. At the K–12 level, private and charter schools are already there. A few states have taken steps to make tenure harder to obtain, or even to move toward its demise. Lawsuits are underway in several more places, and I have no doubt that kindred efforts will continue in both the voting booth and the courtroom.

These HR changes are often framed in term of “making it easier to fire bad teachers”— yet that’s not the main point of radical tenure reform. The number of truly bad apples in the instructional barrel is small. While it’s important that school leaders have the power to shed such people—and not just shift them to other schools, a process known in the field as the “dance of the lemons”—the larger point is that they need to be able to run the kinds of schools that kids deserve to attend at a cost that taxpayers can afford to pay. In addition, a decidedly non-trivial fringe benefit for society would be to bring the profession of school-teaching into the 21st century.