This post is inspired by a recent comment that referred to "financially secure faculty". The context was that graduate students (with their low salaries) are financially insecure but faculty (with their higher salaries) are financially secure.
Of course it's not that simple. Financial security does not correlate exactly with salary; i.e., you can not conclude that because faculty have higher salaries than graduate students, faculty are financially secure. Faculty may be more secure (in some ways) but that is not the same as being financially secure.
Tenured faculty have a certain type of job security because it takes an extreme event (criminal activity; an economic crisis) for a tenured professor to lose their job. Most of us with tenure are therefore in little danger of financial disaster owing to being unemployed.
Nevertheless, some faculty, and in particular early career faculty, struggle to cover the basic costs of living, in part because professors are typically paid for only 9 months of work by our universities. Consider in particular the financial situation of an early career professor with one or more children. Graduate students with families may be in a similar or more difficult situation, but some of my younger faculty colleagues are in financially precarious positions despite their higher salaries. There are many factors in the financial security of any family, including costs of daycare, mortgage, other loans and whether the family relies on one or two incomes (and what those incomes are).
Even mid-career and senior faculty may have serious financial challenges. Some of my colleagues have been dealing with personal financial crises related to the costs of caring for ailing parents and other relatives, college expenses for one or more offspring, the economic consequences of divorce, or the recent devastation of investment-based retirement accounts (the result of which is that some professors cannot afford to retire and continue to have adequate health insurance).
Certainly there are financially secure faculty, especially those who spent some time in administration and retained their higher salary once they returned to their regular faculty positions. And those of us in science or engineering fields tend to have higher salaries than our colleagues in the humanities, in addition to the greater possibility of summer salary from grants. I personally feel financially moderately secure in my two-professor family, although we are somewhat intimidated by the future costs of our daughter's college education and the slow rate at which we are accumulating retirement savings.
I feel fortunate in my job and even in my (9 month) salary. But: You can't generalize about the financial security of faculty just because our salaries are significantly higher than those of our graduate students.
8 years ago