The Heart Goes Last by Margaret Atwood

With unemployment, homelessness, and crime on the rise, Charmaine and Stan's future look nothing but bleak. Living in their car, on the brink of starvation (or worse), and with their marriage quickly deteriorating, the couple finds hope in an ad for Consilience, a new program that promises paradise for its residents through balance and conformity. The terms are simple, in a small gated community, the Consilience project provides participants with a safe home, a job, and a better life. In exchange, each resident must spend a every other month living in the Consilience prison - the idea that prisoner and citizen both play equally important roles in the community and the balance between the two should create a perfectly working society. At first, for Charmaine, Stan, and the other Consilience participants, the experiment seems a godsend, but soon they find out that something more corrupt and sinister is afoot.