Author William Strauss noted that around the time Coupland's 1991 novel was published the symbol "X" was prominent in popular culture, as the film "Malcolm X" was released in 1992, and that the name "Generation X" ended up sticking. The "X" refers to an unknown variable or to a desire not to be defined. Strauss's coauthor Neil Howe noted the delay in naming this demographic cohort saying, "Over 30 years after their birthday, they didn't have a name. I think that's germane." Previously, the cohort had been referred to as Post-Boomers, Baby Busters (referencing the drop in the birth rates following the baby boom), New Lost Generation, latchkey kids, MTV Generation, and the 13th Generation (the 13th generation since American independence).