My guess is some high-paying jobs that were called "Data Scientist" 3 years ago are now called "Data Engineer" and "Machine Learning Engineer", hence the average salary for jobs still called "Data Scientist" goes down a little.
Note the actual percent depends on how you measure it.
In addition to that, I think some lower-paying roles that used to be analysts or BI specialists are increasingly being called Data Scientists. My guess would be if you controlled for skills and job responsibilities you’d see increases.
My guess is some high-paying jobs that were called "Data Scientist" 3 years ago are now called "Data Engineer" and "Machine Learning Engineer", hence the average salary for jobs still called "Data Scientist" goes down a little.
Note the actual percent depends on how you measure it.
Full source/data/code: https://www.kaggle.com/nomilk/data-science-language-and-job-...