When I was hired as an assistant professor in 1969, mandatory retirement at age 65 was the law of the land for tenured faculty members. I was 26 years old at the time, so that seemed impossibly far away. But by the time I was 50, two amendments to federal law had removed all age limits. I could stay in my tenured position forever! That's how, in 2011, I found myself still an active professor at the Massachusetts Institute of Technology (MIT) in Cambridge at age 68. I might still be in my tenured job today, if not for a meeting that year with the official who administered my federal research funding.
“Professors older than 65 were blocking the way of many young scholars.”
The official asked me to investigate how eliminating mandatory retirement had affected the availability of positions for new assistant professors. The question struck me as important but not personally relevant—until my colleagues and I got our results.
Our initial intuition was that there would be no substantial long-term effect. We expected to find that the number of open positions dipped just after the law's two changes. After all, the number of available tenure-track faculty slots is essentially fixed—at MIT, there are approximately 1000. To create room for a new faculty member, an existing one has to leave. But after a brief dip, we thought, retirements should return to normal, creating room for new recruits.
One word for such intuition: wrong! Through modeling, we discovered that eliminating the retirement age had reduced the number of new slots for MIT assistant professors by 19%, from 57 to 46 per year. Put simply, without a mandatory retirement age, senior faculty members are much slower to leave. When our paper was published, I viewed it as just another finding. But eventually, I had serious reflections about what the results really meant.
Around that time, I had hired a postdoc named Navid Ghaffarzadegan. He was a superlative young scholar. Yet he worried that, like many postdocs, he might not be able to get the tenure-track position he sought. There are simply too many applicants seeking too few positions. And I began to realize that I and other professors older than 65 were blocking the way of many young scholars who seek academic careers. I started to wonder whether it was time for me to step aside, but the idea of leaving the job I had been tied to for so long was hard to swallow. (In the meantime, Navid secured that tenure-track position and is now an associate professor with tenure.)
Then, the dean of the engineering school heard about our paper and asked me to go over the details with him. It must have resonated with him, because he briefed the department heads about the need for a flexible after-tenure option that would vacate a position and open the way for a new hire. They soon invented “professor, post-tenure,” tossing out an earlier option with the horrendous name “professor without tenure, retired,” or PWOTR, pronounced “pee-water.”
Once “professor, post-tenure” was announced in 2016, I found it increasingly attractive. It wasn't the same as “emeritus”—not full retirement. I could retain my office, teach and supervise students, and be a principal investigator on research grants—all with great flexibility. I would get to choose which projects I wanted to do and be paid accordingly, up to 49% of my previous salary. I could also access retirement and pension funds. My wife and I would be able to spend more time together and with our children and grandchildren. Decision made!
I submitted my tenure resignation in 2017. I've enjoyed every minute since, busy as ever but only on activities I select—such as MIT BLOSSOMS, a project I co-founded to create interactive video lessons for high school math and science classes. I feel lucky to have this option. Too few institutions offer these types of transitional positions to ease the challenge for us senior professors. At 74, I in essence removed 9 years from someone else's career. I should have stepped aside sooner.