The sampling frame was based on a 2004 count, but the population has been changing rapidly and dramatically because of sectarian violence, the flight of refugees, and overall population migration. Another source of bias in household surveys is underreporting due to the dissolution of some households after a death, so that no one remains to tell the former inhabitants' story. Mortality estimates that are derived from surveying deaths of siblings were also calculated, but this method may also be subject to such underreporting. ...