I'm struggling to remember a story that I know I read. There's a small chance it was a story being told within a larger narrative, but I'm reasonably certain it was a stand-alone short story.
The premise is that astronomers discover a planet that seems to contain the reincarnated dead. They determine this by spotting several famous people - Marilyn Monroe, Kurt Cobain, etc.
If I recall, they also determine that you only get there after a certain amount of suffering or rebirths, so a decision is made on a global scale to speed up the process through a program of global euthanasia. If there's no more rebirth, well, everyone gets to go to paradise, right?
Some countries (especially poorer ones in Africa and South America) don't cooperate, so the governments of the world...help them along. Domestically, they issue cyanide pills to citizens.
The story is told from the point of view of a teenage girl who lives in the suburbs with her parents and younger brother. The parents decide the whole family will go together using the "running car in a closed garage" trick. The girl escapes and goes to meet with her boyfriend, and the stinger at the end is (I think) that she's pregnant, and therefore the cycle will continue anyway.