Aerospace and semiconductor disciplines enjoy the highest median earnings, at $110,000 and $95,473, respectively. Civil/environmental falls at the opposite end of the spectrum, with a median salary of $35,474.
The two most important factors driving salary gaps across disciplines are employment sector 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 systems engineering) have 663 people at for-profits versus 314 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, 294 out of 331 workers are located in higher-income countries.