An interesting bit of history on the expression "There’s no such thing as a free lunch"

From an interview (pdf) with Milton Friedman.

QUESTION: Can you tell us—I don’t happen to know—under what circumstances you first said the famous words “There’s no such thing as a free lunch”?

FRIEDMAN: Peggy Noonan, who has written some very good words that you have all heard such as “Read my lips”—it’s too bad she wasn’t able to enforce the words she wrote—asked me if I could remember when I first used the words “There’s no such thing as a free lunch.” The answer is no, I don’t remember. However, I am not really the originator of that statement. A colleague of mine at the Hoover Institution traced it back to some time in the nineteenth century in the parlance of saloons: If you bought a beer, they would give you a free lunch. That’s where the phrase originally came from. It was made popular by Robert Heinlein, a science fiction writer who wrote a wonderful novel called The Moon Is a Harsh Mistress. The novel’s setting is a settlement on the moon that revolts using the motto TANSTAAFL (There ain’t no such thing as a free lunch). I may say that the revolution was a success because of a wonderful near-human computer.