[1][2] The term was coined by behavioral economist Richard Thaler and legal scholar Cass Sunstein in a 2003 article in the American Economic Review.
[3] The authors further elaborated upon their ideas in a more in-depth article published in the University of Chicago Law Review that same year.
It is libertarian in the sense that it aims to ensure that "people should be free to opt out of specified arrangements if they choose to do so" (p. 1161).
Thaler and Sunstein published Nudge, a book-length defense of this political doctrine, in 2008 (new edition 2021).
For example, it has been argued that it fails to appreciate the traditional libertarian concern with coercion in particular, and instead focuses on freedom of choice in a wider sense.