I'm looking to identify an SF-nal short story I once read; it was just a few pages long, divided into four segments. Each segment described a world where "nobody could die unless..." some particular condition. I'm don't really remember the specific conditions, but they were on the lines of "nobody could die unless he specifically chose to" or "nobody could die as long as he had any money."
Three of the four scenarios had bleak endings, exposing the proposed system as self-destructive (in one way or another). The last had a condition related to love - I think it was "nobody could die as long as somebody loved him," or maybe "as long as he loved somebody else," and that one had more of a happy ending.
I have a vague recollection that the story was by Joe Haldeman, but I'm quite likely to be mistaken. I remember first finding it in a random "best SF of the year" anthology (I don't recall which, but certainly something within the past decade), and then finding it reprinted online. Finding the online reprint, if it's still around, would be especially nice - but I'll settle for identification.