The following is a guest post* by Daniel Hicks (UC Davis), in which he explains how it could be that, contrary to conventional wisdom, there aren’t enough people getting PhDs in philosophy.
The Underproduction of Philosophy PhDs
by Daniel Hicks
One common explanation for the continuing structural employment problem for philosophy PhDs is that there are “too many” philosophy PhDs. That is, according to this explanation, the supply of philosophy PhDs (i.e., the number of new PhDs) is greater than the demand (specifically, the need for people with PhDs in philosophy to teach philosophy classes). One way to empirically check this explanation is to look at the tenure-track employment rate—what fraction of recent philosophy PhDs are employed as tenure-track faculty? Insofar as this rate has gone down and remains low, this suggests that the field has been overproducing PhDs.
But this empirical check ignores the phenomenon of casualization or adjunctification. That is, instead of hiring tenure-track faculty to teach, colleges and universities have hired adjuncts and other contingent faculty. Given this phenomenon, the number of new tenure-track positions in philosophy doesn’t necessarily reflect changes in the demand for philosophy teachers. So the tenure-track employment rate is not a good measure.
A more accurate way to measure demand for philosophy teachers would be based on total student enrollments in philosophy courses. However, as far as I know these data aren’t publicly available, either nationally or for individual schools. I suggest the number of bachelor’s degrees in philosophy could be a useful proxy for total course enrollments. These data are publicly available from IPEDS. This assumes that the ratio of philosophy majors to total enrollments in philosophy courses is roughly constant. But, given that assumption, changes in the ratio of new BAs to new PhDs can give us a sense of whether philosophy has recently been producing “too many” PhDs. Specifically, if this ratio is much lower today than it was, say, 25-30 years ago, then this is an indicator that the field has overproduced PhDs.
In fact, the opposite appears to be the case. Over the last 15 years, the bachelors:PhD ratio was elevated, suggesting that the field has underproduced PhDs. This is not the case in all fields.
For comparison, in this post I examine electrical engineering, English, biology, mathematics and statistics, physical science, and sociology, as well as philosophy. I use IPEDS data from 1984 through 2016. As of December 15, 2017, the IPEDS data for 2016 are provisional. I use simple sums to calculate the number of bachelor’s degrees and PhDs in these fields in each year. This produces slightly higher numbers than Eric Schwitzgebel reports in this post using the same data; usually the difference is 50 bachelor’s degrees or fewer. Since Schwitzgebel does not fully document his methods, I can’t tell where this discrepancy comes from.
The first plot below shows the total number of bachelors degrees, by field and year. The plot shows a dramatic rise in biology; a sharp drop-off in physical science in the 1980s, followed by a gradual increase; and more-or-less stable numbers across the other fields.
Next we plot total PhDs. Again, there is a dramatic rise in biology, and smaller increasing trends for most other fields. Physical science is much more prominent in this plot than in the bachelors plot.
Now we move on to the ratio of new bachelors degrees to new PhDs. Again, we are using bachelors degrees as a proxy for the total demand for philosophy teachers. Comparing this ratio for recent years (the right-hand side) to 25+ years ago (the left-hand side) gives us an indication of whether these fields have been overproducing or underproducing PhDs. If the ratio is lower today than 30 years ago, this suggests that supply (PhDs) has increased relative to demand (bachelors), and so the field has been overproducing PhDs. But if the ratio is higher today than 30 years ago, this suggests that demand has increased relative to supply, and so the field has been underproducing PhDs.
Working from top to bottom, the long-term trends for sociology and (to a lesser extent) English is an increasing ratio. This suggests that these fields have been underproducing PhDs. This story is somewhat more complicated for English, which shows large peaks and troughs.
In contrast, electrical engineering and math had decreasing ratios in the first 15 years of the data, and recently have been more-or-less flat. Physical science follows a similar but more mild pattern. This suggests that these fields overproduced PhDs.
Philosophy shows a cyclical pattern, similar to English. During roughly 2002-2010, philosophy’s ratio was higher than during 1985-2000, suggesting that the field underproduced PhDs. The ratio has decreased slightly in the last few years, and today appears to be roughly where it was in the early 1990s.
Finally, the ratio for biology has been nearly flat. While the number of PhDs in biology increased dramatically over the last 20 years, so did the number of bachelors degrees.
Because the ratios for different disciplines are on different scales, it may be easier to interpret a normalized ratio. In the following plot, for each field, we first calculate the mean ratio over the first ten years of the data (1984-1994), then divide the ratio in a given year by this mean.
As with the previous graph, if this normalized ratio is high—above the dashed line at 1.0—that suggests that the field has underproduced PhDs. This appears to be the case for sociology, philosophy, English, and biology; although philosophy has increased only slightly relative to the 1984-1994 baseline, and English has recently dropped just below this baseline. There appears to be chronic overproduction in physical science, math, and electrical engineering.
So, against the common explanation for the structural unemployment problem, this analysis suggests that philosophy (along with English, biology, and sociology) has produced too few PhDs, rather than too many. This suggests, I think, that the right way to address the structural unemployment problem is to focus on de-adjunctification—that is, pushing colleges and universities to turn short-term, part-time teaching contracts into long-term, full-time teaching positions, and to turn long-term, full-time teaching positions into tenure-track faculty positions. This push is likely to be most effective by organizing strong faculty, adjunct, and graduate student unions. But that is a topic for another post.