Curiously, the failures of Communism are more often treated as a joke than as a tragedy. (As in the current jollity: What would happen if the Communists occupied the Sahara? Answer: Nothingfor 50 years. Then there would be a shortage of sand.)
It appears that this was a unattributable saying, perhaps originating in the old Soviet Union as an Indian news source published in January of the same year, 1971, under the title of "Dry Humor" the following;
"Here is another direct-from-Moscow Iron Curtain quip. Question: What will happen when Communism comes to the Sahara?
Answer: Nothing for 50 years, and then there will be a shortage of sand.
Finally we get the 'matching' quote from Dr Milton Friedman in 1980 as published in his column for Newsweek;
If you put the federal government in charge of the Sahara Desert, in 5 years there'd be a shortage of sand