Ethiopia-born Mengestu has written the novels How to Read the Air, in which a now adult child of Ethiopian immigrants retraces his parents steps, and The Beautiful Things that Heaven Bears, about an Ethiopian refugee searching for a sense of society in Washington DC.
Diaz, who is an established short story writer from the Dominican Republic, has already won a Pulitzer for his footnote-laden novel of a Dominican boy growing up in New Jersey, The Brief Wondrous Life of Oscar Wao, and has another called Monstro in the works.
Previous literary winners include Yiyun Li (A Thousand Years of Good Prayers), Deborah Eisenberg (The Collected Stories of Deborah Eisenberg), Stuart Dybek (I Sailed With Magellan).