SpongeBob SquarePants first made a public appearance in 1999, but it took quite some time for the emergence of a scholarly work which directly cited the character as a primary focus for study. This one, from 2005, is a likely candidate as the first :
■ A More Porous Postmodernity: Absurdity, Politics, Consumerism and the Cultural Authority of Spongebob Squarepants
Since then, SpongeBob SquarePants has definitely not been ignored by academia. Here’s a (partial) list of example contributions (in no particular order).
■ Consumption, Health, and Disposability in SpongeBob SquarePants
■ Absurdism in Spongebob Squarepants episode club Spongebob
■ SpongeBob SquarePants: pop culture tsunami or more?
■ An Analysis of Expressive Utterances Produced by the Characters in the Movie Entitiled [ sic] Spongebob Squarepants ( A Pragmatic Study)
■ Of Theory and Praxis: SpongeBob SquarePants and Contemporary Constructions of the American Dream
■ Constructing gender and relationships in “SpongeBob SquarePants”: Who lives in a pineapple under the sea?
■ Analysis of Deixis in The SpongeBob SquarePants Movie: a pragmatic approach
■ Social Mores and SpongeBob Squarepants
■ Popular culture and management: the provocation of pongeBob [ sic[ SquarePants
BONUS : The ruling of the U.S. Court of Appeals for the Fifth Circuit, 2008, on the case of “The Krusty Krab” (an underwater restaurant in the SpongeBob SquarePants series).
Research research by Martin Gardiner