Mystery Book Solved

It's In the Country of Last Things by Paul Auster

"The novel takes the form of letter from a young woman named Anna Blume to a childhood friend or sweetheart. Anna Blume has ventured into a city (unnamed, but possibly New York) that has collapsed into chaos and disorder. In this bleak environment, no industry takes place and most of the population collects garbage or scavenges for objects to resell. City governments are unstable and seem to be concerned only with collecting human waste and corpses for fuel. There are various suicide cults like the Runners and Leapers. Anna Blume has entered the city to search for her brother William, a journalist, and it is suggested that the Blumes come from a world to the east which has not collapsed. The 'last things' in the title of the book refers not only to the disappearance of manufactured objects and technology but also the fading of memories of them and the words used to describe them."