In 1991, Carl Sagan was nominated for membership in the National Academy of Science but was denied admission, lacking enough endorsing votes. It was the Academy’s rejection of Sagan, along with Harvard’s prior denial of his tenure, that made Sagan’s biographers talk about the phenomenon which has become known as the Sagan Effect: “the perception that popular, visible scientists are worse academics than those scientists who do not engage in public discourse. Yet, later analyses of Sagan's output have indicated that his academic contributions compared favorably to those of other Academy members.”