promotion up union-negotiated payscales, usually with automatic advancement towards the top of a grade, with the luckier faculty members being on 'permanent contracts' with no end-date. To go to the next grade (e.g. from associate professor to professor), an application must be submitted, and the criteria are as exacting as in North America. Simon Batterbury argues this system offers less opportunity for sabotage, and more adherence to social justice goals, even though 'permanent' staff members can be fired at any time. Invisible labor Invisible labor (aka invisible work) in academia refers to the work carried out by collegiate faculty that largely goes unrecognized in terms of tenure evaluation. Two major examples of invisible labor are student mentoring and university diversity/inclusionary work. Though student mentoring and inclusion are important aspects to student success, these tasks are often undervalued in faculty evaluations when compared to other academic work, such as publishing research and attaining grant money. This labor is often carried out disproportionately by faculty from marginalized backgrounds. While the majority of professors agree that diversity is very important to education, most of the diversity and inclusionary work is carried out by non-male, non-white, and first-generation faculty. Because of their diverse backgrounds, professors from marginalized backgrounds often experience increased pressure in performing diversity service tasks, while being held to the same standards for promotion. While diversity among students has been increasing, the rate of diversity among professors has progressed at a much slower pace. This disparity places a greater demand on minority professors to mentor students, who often seek out mentors from a similar background. Intersectionality appears to play a role in invisible labor, as professors with multiple marginalized identities experience increased pressure to engage in low-promotability work. Defenses of tenure for college professors Defenders of tenure, like Ellen Schrecker and Aeon J. Skoble, generally acknowledge flaws in how tenure approvals are currently run and problems in how tenured professors might use their time, security, and power; however, as Skoble puts it, the "downsides are either not as bad as claimed, or [are] costs outweighed by the benefits"—and he points out that the very debate about tenure in which he is engaging is made possible by the academic freedom which tenure makes possible. "Tenure remains scholars' best defense of free inquiry and heterodoxy," writes Skoble, "especially in these times of heightened polarization and internet outrage. Let us focus on fixing it, not