Horwitz was the Distinguished Professor of Free Enterprise in the department of economics in the Miller College of Business at Ball State University in Muncie, Indiana.

He consulted with other schools on living-learning programs and on teaching research and communication skills to first-year students.

In fall 2017, Horwitz joined the department of economics at Ball State University as distinguished professor of free enterprise.

Horwitz was a long-time faculty member at the summer seminars of the Institute for Humane Studies and the Foundation for Economic Education.

Horwitz was a senior affiliated scholar of the Mercatus Center at George Mason University in Arlington, Virginia, where he had conducted research on the role of Wal-Mart[3] and the Coast Guard in the response to Hurricane Katrina.

His "Open Letter to My Friends on the Left"[6] in September 2008 was a widely read libertarian analysis of the mortgage crisis and has been translated into five languages.

[10] Outside of his professional interests, Horwitz was a fan of hockey, especially the Detroit Red Wings, and classic rock, especially Rush.

[1] He was married to Sarah Skwire, a senior fellow and director of communications at Liberty Fund, and they resided in Fishers, Indiana, with her two daughters.