Dan Jacoby (former Harry Bridges Chair of the Harry Bridges Center for Labor Studies, and Professor Emeritus of Interdisciplinary Arts and Sciences at UW Bothell) published an Op-Ed in Inside Higher Education concerning the potential impact of a federally registered apprentice program for graduate students seeking their PhD. 

The article is titled "A Real Faculty Apprenticeship," and examines the historic supply-side issues regarding graduate programs, as well as how an apprenticeship approach may positively impact students and the universities and colleges that are their current or future employers. From the article: 

The past 50 years have created a new normal for faculty. Where labor unions once complained that two-track systems allowed lower standards for new hires compared to old-timers, academia has built not one or two, but many, faculty tracks. At my institution, the University of Washington, faculty titles now include tenure-track professors, teaching professors, research professors, professors without tenure, clinical professors, temporary lecturers (part- and full-time), part-time non-temporary lecturers, professors of practice, and teaching associates. This maze of titles is hierarchically structured so that those on the bottom often experience no or limited governance rights, short-term contracts, and no upward path of progression. 

To read the full article, visit Inside Higher Education.