“What’s the difference between communism & a pencil?”/“The pencil works on things other than paper.”

It’s sometimes said that communism works on paper, but not in reality. A riddle was posted on Reddit—Jokes on December 10, 2015:
 
Q: What’s the similarity between communism and a pencil?
A: They both only really work on paper.
 
The slightly reworded riddle was posted on Reddit—Jokes on November 5, 2019:
 
Q: What’s the difference between communism and a pencil?
A: The pencil works on things other than paper.
   
     
Reddit—Jokes
Posted by u/trill_cosby420 December 10, 2015
What’s the similarity between communism and a pencil?
They both only really work on paper
 
Twitter
me
@not_actuallyme
What’s the similarity between communism and a pencil? via /r/Jokes http://ift.tt/1OSwmaF
12:46 AM · Dec 10, 2015·IFTTT
     
Twitter
Living Sarcasm
@SarcasmLiving
What’s the similarity between communism and a pencil?
They both only really work on paper
12:32 AM · Nov 2, 2016·Twitter for Android
 
Reddit—Jokes
Posted by u/h77IM November 5, 2019
What’s the difference between communism and a pencil?
The pencil works on things other than paper.
 
Twitter
Lame Jokes
@lamejokes_net
What’s the difference between communism and a pencil? : The pencil works on things other than paper.
1:25 PM · Nov 5, 2019·IFTTT