Ken Kesey’s 1963 novel, One Flew Over the Cuckoo’s Nest, questions whether the individuals managing psychiatric institutions are actually more rational than their patients. Kesey’s book reflects the growing cynicism of the two decades since Harvey: its main character resembles a dangerous sociopath rather than a charming eccentric, and the asylum is depicted as a place where inmates are drained of their individuality.

Arsenic and Old Lace is another comedy about eccentrics that emerged around the same time (it was adapted into a film the same year Harvey premiered on Broadway). The story revolves around two elderly aunts who invite lonely bachelors to their home and then poison them. The script can be found in a 1995 edition from Dramatists’ Play Service.

John Patrick Shanley, a contemporary playwright, shares a whimsical and imaginative style similar to Mary Chase. His finest works are compiled in 13 by Shanley (1992), available from Applause Theater Book Publishers.

The renowned Irish poet William Butler Yeats explored Celtic mythology in his 1892 collection, Irish Fairy and Folktales, which may have been one of Chase’s sources for information about the pooka. Yeats’ book is available in a 1995 paperback edition from Barnes and Noble Books.

Shakti Gawain’s book Creative Visualization (1983) is one of the most influential "self-help" books, based on the concept that Elwood P. Dowd utilizes in this play: the idea of turning the imaginary into reality.