It is not known who coined the nickname.
(New York Review of Books website)
29 December 1969, New York Times, pg. 27:
Certain familiar criticisms of The New York Review of Books are exaggerated. It was unfair to call it The New York Review of Each Other's Books. True, the cast of reviewers is finite, but a check of the index reveals that well over 500 people, ranging all the way from tepid liberals to extreme radicals, have contributed during the review's first six years.
24 March 1974, New York Times, pg. 370:
Cleverly and, broadly speaking, appositely, Nobile divides the Review's life hitherto into five phases: "The New York Review of Each Other's Books," the initial phase when friend reviewed friend, usually kindly;...
12 December 1984, Washington Post:
For years, a number of New York intellectuals wanted to create a book review to rival London's Times Literary Supplement. Hardwick, in an article written for Harper's in 1959, decried the decline of book reviewing and wrote that "sweet bland commendations fall everywhere upon the scene . . . a universal, if somewhat lobotomized, accommodation reigns."
The 1962-1963 newspaper strike in New York provided Ellsworth, Silvers and the Epsteins with their opening. With the New York Times Book Review unavailable, the new magazine attracted advertisers easily. The writers wrote for free at first and the founders, all of them well connected to the well-read and well-fed, found investors quickly. Among the authors appearing in the first issue were Norman Mailer, William Styron, Robert Penn Warren, Mary McCarthy, Irving Howe, Paul Goodman, Alfred Kazin, Susan Sontag, Gore Vidal and Dwight Macdonald.
The magazine became so popular so fast that when the strike ended, advertising revenue fell off by only 10 percent.
Philip Nobile, who wrote a book about the magazine called "Intellectual Skywriting," chided the New York Review for using so many English critics and claimed the Review went through distinct periods when it could have been called The New York Review of Each Other's Books, The London Review of Books and the London Review of Vietnam.
1 March 1995, Direct Marketing, "In the mail" by James R. Rosenfield, pg. 43:
This month the author examines four mailings he received from The New York Boor Review.
Back in the 1960s, we used to call it The New York Review of Vietnam. In the '70s, wags dubbed it The New York Review of Each Other's Books. In the '90s, I'm not sure anyone cares enough to make fun of them, which perhaps is the reason The New York Review of Books wants me so badly as a subscriber.
May 1997, Playboy, Saul Bellow interview, pp. 59+:
PLAYBOY: Let's turn to literary politics. Is there a literary establishment today?
BELLOW: No. There are poor shreds of it at The New York Review of Each Other's Books.