Rite of Passage Author:Alexei Panshin In 2198, one hundred and fifty years after the desperate wars that destroyed an overpopulated Earth, Man lives precariously on a hundred hastily established colony worlds and in the seven giant Ships that once ferried men to the stars.
This is a coming-of-age story set in the far future. The main characters are a boy and girl who live on a space ship that had started life as a colony transport taking people from Earth to their new homes. Earth has been pretty much destroyed by over-population in this future, so the one rule that the people on the space ship live by is "population control." They trade their knowledge and the history from Earth to the various colony worlds for things that they need (foodstuffs, fabrics, etc.)
In order to be considered an adult and allowed to remain on the Ship, you must pass the titular "Rite of Passage." The story deals with our mc's training and preparation for (and then survival of) that Rite.
Excellent story with many thought provoking ideas.