Why are some of the Three Stooges jokes in the Abbott and Costello movies?

The Three Stooges and Abbott and Costello did Burlesque before they were on television so some of their jokes should be similar but some are exact copies. It couldn't have been caused by writers because Moe did most of the writing for the Stooges and Costello was the writer for his movies.





If it were the writers Red Skelton and Bob Hope, who did Vaudville, would have had more copies than they did and the Marx Brothers who also did Vaudville never had any of the same jokes. It's clearly not the writers who did the joke swapping. Could it have been Joe Besser or Shemp? They worked for the Stooges and Abbott and Costello and I've read somewhere that it was Shemp. What's the story behind that?

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