Postdocs are the workers of academia. They are the main players beyond the majority of scientific papers published in journals and conferences. Yet, their effort is often not recognized in terms of salary and benefits.

A few years ago, the NIH has established stipend levels for undergraduate, predoctoral and postdoctoral trainees and fellows, the so-called NIH guidelines. Many universities and research institutes currently adopt these guidelines for deciding how much to pay postdocs.

One of the key problem of the NIH guidelines is that they are established at a national level. This means that a postdoc in Buffalo is paid the same than a postdoc in Boston, despite Buffalo is one of the most affordable city to live in the USA, while Boston is one of the most expensive. Every year, the NIH releases new guidelines, where the stipends are slightly increased. Do these adjustments help a postdoc in the Boston area take home a bit more money?

I have used Matplotlib to plot the NIH stipend levels (y axis) for each year of postdoctoral experience (x axis) for the past 4 years of NIH guidelines (color). I have also looked at the inflation of years 2017–2019 and increased the salaries of the previous year by that percentage (dashed lines). Plot of the NIH stipend level for postdoc versus the number of years of postdoc experience for every year from 2016 to 2019 inclusive. The x-axis ranges from 0 to 7 years of experience. The y-axis ranges from $45,000 USD to $60,000 USD. The plot also shows how these salaries would increase according to the rate of inflation during the same years. The overall message is that postdoc salaries are adjusted for inflation nationally.

The data revealed that the salaries of 2017 were just increased by the inflation rate for the most senior postdocs, while junior postdocs (up to 1 year of experience) received an increase more than 2.5 times of the inflation. In 2018, all salaries were just adjusted to the inflation. In 2019, the increase was slightly higher than the inflation level. So, overall, every year the NIH makes sure that the postdoc salaries are, at least, adjusted to the inflation. Great!

As mentioned earlier, there are cities in the US that are more expensive than others, for example Boston. To partially account for such differences when looking at the postdoc salaries, I subtracted from each salary the average rent for a one-bedroom apartment in Boston. Of course, it also increases every year, but, unfortunately for postdocs, rent increases way more than the inflation. The results are below. This plot is similar to the previous plot, but has adjusted the y-axis by subtracting the cost of rent in Boston. Plot of the NIH stipend level for postdocs minus the average rent in Boston versus the number of years of postdoc experience for every year from 2016 to 2019 inclusive. The x-axis ranges from 0 to 7 years of experience. The y-axis ranges from $8,000 USD to $22,000 USD. The overall message is that increases in rent in Boston have outpaced increases in NIH stipends.

It turns out that the best year for postdocs with at least one year of experience was actually 2016. In the subsequent years, the real estate has eaten larger and larger portions of the postdoc salary, resulting in 2019-paid postdocs taking home 20% less money than 2016-paid postdocs with the same experience.

In the end, life is financially harder and harder for postdocs in the Boston area. These data should be taken into account by research institutes and universities, which have the freedom of topping up postdocs’ salaries to reflect the real cost of living of different cities.

You can download the Jupyter notebook [here](Postdoc salary Analysis.ipynb).