A classic libertarian joke is:
 
Q: How many libertarians does it take to screw in a light bulb?
A: None. The free market will do it.
 
The joke has been cited in print since at least 1981 and is of unknown authorship.
 
[This entry was prepared with the research assistance of the Quote Investigator.]
 
 
Libertapedia: Libertarian Jokes
Light bulb jokes
How many Libertarians does it take to screw in a light bulb?
“None. The Market will take care of it.”
 
30 August 1981, Washington (DC) Post, “Libertarians, With Eye on Voters, Debate Need to Be More Radical” By T.R. Reid, pg. A8, col. 3:
This principle is so basic to all factions that the party has its own version of a standard joke, to wit: “How many Libertarians does it take to screw in a light bulb?” Answer: “None – the free market will take care of it.”
 
21 January 1982, Dallas (TX) Morning News, “Supply-side may not be Reagan’s side anymore” (New York Times - News Service), pg. D1, col. 4:
As the question of the hour puts it: “How many supply-side economists does it take to screw in a light bulb?” The answer: “None. The free market will do it.”
   
Google News Archive
22 March 1985, Anchorage (AK) Daily News, pg. B11, col. 4:
Question for Andre Marrou: How many Libertarians does it take to change a light bulb? Answer: None. The free market will do it.
—H. W. Gabiel
 
Google Books
Man, Economy, and Liberty:
Essays in Honor of Murray N. Rothbard
Edited by Llewellyn H. Rockwell, Jr. and Walter Block
Auburn, AL: The Ludwig von Mises Institute
1988
Pg. 195:
Q: How many Libertarians does it take to screw in a light bulb?
A: None. The free market will do it.
 
Google Books
The Transient and Permanent in Liberal Religion:
Collected Papers of the UUMA Convocation on Ministry
By Dan O’Neal, Alice Blair Wesley and James Ishmael Ford
Boston, MA: Skinner House Books
1995
Pg. 155:
To the question “How many libertarians does it take to screw in a light bulb?” the answer is “None. Market forces take care of it.” Not so.
   
Google Groups: alt.politics.libertarian
Libertarian humor needed
Wyatt Earp
10/19/96
This is the only Libertarian joke Ive heard (and can remember) and its not really even funny.

Q: How many Libertarians does it take to change a lightbulb?
A: It doesnt matter, if it isnt my lightbulb, im not fixing it.
(...)
Glen Raphael
10/22/96
The version of this that qualifies as a joke, albeit not a sympathetic one, is:
 
Q: How many Libertarians does it take to change a lightbulb?
A: None, the market will take care of it.
 
Google Books
The Greatest Joke Book Ever
By Mel Greene
New York, NY: Avon Books
1999
Pg. 185:
How many Libertarians does it take to screw in a lightbulb?
None, because somebody might come into the room who likes to sit in the dark.
   
AmericanEconomicAlert.org
Intellectual Deception Reveals Weakness of Free Trade Ideology
William R. Hawkins
Sunday, February 01, 2004
(...)
As the old joke goes, “How many libertarians does it take to change a light bulb?” The answer is, “None, they just sit in the dark and wait for the invisible hand to do if for them.” But as the “invisible hand” turns off the lights in one factory after another in America, the intellectually dishonest Reynolds has the temerity to deny that it is dark at all.
 
Google Books
Anarchy And the Law:
The Political Economy of Choice
By Edward Stringham
Oakland, CA: The Independent Institute
2007
Pg. 152:
Most libertarians have heard the joke: “How many libertarians does it take to change a light bulb?” “None, the market will take care of it.”
 
Bacon’s Rebellion
Looking for Libertarian Jokes?
Posted on June 9, 2012 by Peter Galuszka
How many Libertarians does it take to change a light bulb? None! If the bulb needed changing, the free market would have done it.