No to Ethics of Liberty.
Depending on your judgment about how much time he’s willing to commit to this initial exploration, starting from the longest:
-
Human Action (politics AND economics). I would be very careful about recommending it as the first book on his journey. Personally, I found it to be much deeper and more profound the second time I read it (five years after the first reading, and after some major thought germination in between.)
-
Economics in One Lesson (economics)
-
Beyond Democracy (politics) …($0.99 on Kindle. Free reader app for all devices available.). Shorter but, IMO, a much more effective version of Hoppe’s Democracy: The God That Failed, especially for initiation. I’ve been plugging this book here lately simply because I’ve had extremely good results initiating friends into the concept of freedom with it. Very approachable and very well written, too. Has a large paradigm shift potential per page written.