William Hummel has a BA in Physics from the University of California Berkeley, studied electronics at Harvard, naval radar at MIT and obtained an MS in electrical engineering from University of Southern California.

Hummel served as a US Navy radar officer in World War II, Pacific Theatre. He spent forty-three years in aerospace engineering, guided missiles and spacecraft, mostly with Hughes Aircraft Company in El Segundo, CA. He served as chief scientist of Control Systems Laboratory, where he designed flight control systems for missiles, first soft landing on moon, orbiting solar observatory, Venus and Mars spacecraft and several geo-synchronous communications satellites. Hummel retired in 1990.

He is currently interested in understanding money and credit, post-Keynesian economics and long-term investing.

Hummel is the host of the popular website Money - What it is, How it works (http://wfhummel.net/).