Tenure, or guaranteeing a college professor a job for life, is under fire in some U.S. states.

A lawmaker in Missouri, Rick Brattin, has proposed a law that would ban tenure at public universities in Missouri after January 1, 2018. Similar initiatives are underway in Wisconsin and Iowa.

Brattin said he feels the costs of higher education in the U.S. have gotten too high. He calls tenure at public universities ?un-American? and an unnecessary cost to taxpayers.

?You cannot tell me that every tenured professor is absolutely doing everything to the fullest extent,? said Brattin, a Republican state representative in Missouri. ?So to have a system in place that protects that person with a guaranteed lifetime employment, it works against itself.?

Opponents say ending tenure would cut jobs in higher education and reduce teaching quality.

?Doing away with tenure and cutting state support is a job killer in higher education,? said University of Missouri biology professor Mannie Liscum in a letter to state legislators. ?Killing higher education is shortsighted for a state, because our innovation declines, our ability to compete declines and our respect declines."

The track to tenure is long and laborious, and not even half of all college professors achieve tenure. College teachers spend seven or more years proving their teaching abilities and the value of their research. That rank gives them job security and academic protection until they voluntarily retire.

?What people fail to understand is that tenure is one of the important fortifications of American democracy, in that in the areas of arts and sciences and literature, universities are a bastion for intellectual freedom," Joe Gorton, an associate professor of criminology at the University of Northern Iowa, told Inside Higher Education. "When tenure ends, the politically powerful or economic elite can control what goes on in universities.?

Blogger and educator John Warner, who penned a column titled, "End Tenure, Before It's Too Late," argues that tenure has lost its way by creating a two-tiered system in higher ed. Only professors with tenure enjoy protection on academic freedom, he writes.

"We all agree tenure is important, maybe even necessary, except that somewhere around half of all faculty now don?t have access to tenure," wrote blogger John Warner in Inside Higher Education, "and therefore do not have those protections."

The National Education Association (NEA) agrees that tenure needs revision.

"Colleges and universities also need to do a better job of setting concrete goals, evaluating successes and failures, and talking plainly to the public about them," it wrote on its website. "Professors who have tenure, just like anyone else, need to be held accountable for their performance."

The "real reason" legislators want to end tenure, the NEA argues, is to save money. "And the real effect is to lower standards."

States generally spend 13 percent of their total budget on higher education, according to the Center on Budget and Policy Priorities. (About 25 percent goes to elementary and secondary education.) Revenue for colleges is raised through tuition, fees and donations.

"When a tenured professor retires or a new position is created, too often the new position is not put on the tenure track. ... Part-time faculty are not unqualified, but they are exploited. Most part-time faculty earn very low 'per course' salaries and few, if any, benefits."

Part-time faculty and adjuncts cannot advise students or contribute adequately if they are employed in various locations, the NEA says. It pointed to a national survey that said "one half of part-time faculty do not hold office hours or meet with students outside the classroom."

A paper published by the National Bureau of Economic Research in 2013 -- "Are Tenured Track Professors Better Teachers?" -- reported that 57 percent of faculty were tenured. By 2009, that number had dropped to 30 percent.

Joerg Tiede, who oversees academic freedom and tenure issues for the American Association of University Professors (AAUP), points to the growing number of administrators and their increased salaries as another reason why state legislators want to decrease tenured professors and their salaries.

A 2013 survey of administrators' salaries by the College and University Professional Association for Human Resources (CUPA) showed that the chief executive officer (CEO) of a university system is paid an average of $388,000. For a CEO at a single institution within a campus system, the pay was on average $290,000.

Tenure became a practice after World War Two, but may professors lost their jobs in the 1950s and ?60s after expressing political beliefs. The U.S. Supreme Court boosted tenure in 1972 as a legally binding contract between a teacher and her or his institution that requires a lengthy and complex process to break.

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