Aerospace and semiconductor disciplines enjoy the highest median earnings, at $112,764 and $102,777, respectively. Civil/environmental falls at the opposite end of the spectrum, with a median salary of $49,893.
The two most important factors driving salary gaps across disciplines are organization type and country income level. The highest-paying disciplines have much higher representation at for-profit companies: The top three disciplines by pay (aerospace, semiconductor, and chemical) have 335 people at for-profits versus 190 combined in government/military and academia.
Country income level has a similar impact on median salaries of optics and photonics disciplines. In the highest paid category, aerospace, 86% of workers are located in North America or higher-income European countries.