An enormously popular writer throughout the 1920s (and a notorious one, also, thanks to his sensational novel "The Green Hat"), he largely gave up writing thereafter, having a dread of writer's block. Both Noel Coward and Ernest Hemingway acknowledged a debt to him - Coward because Arlen had helped finance the original production of "The Vortex", the play that made Coward famous, and Hemingway because Arlen had introduced him to the woman upon whom Hemingway had based the character of Lady Brett Ashley in his first novel, "The Sun Also Rises".