135 Under-five mortality estimates for Sudan and South Sudan Thomas Spoorenberg* and François Pelletier* AbStrAct Objective: To propose a first set of consistent time-series of under-five mortality estimates for Sudan and South Sudan from the 1950s up to today. Methods: Following the estimation procedure of the United Nations Inter-agency Group for Child Mortality Estimation (IGME), a local weighted regression is fitted on empirical under-five mortality estimates derived from the 1955-56, 1973, 1983, 1993, and 2008 censuses and sample surveys. Findings: Since the 1950s, despite two lengthy civil wars (1955-1972 and 1983-2005), the under-five mortality has declined in both Sudan and South Sudan. From a slow decline between 1950 and the mid-1980s, the reduction accelerated thereafter, especially in South Sudan. In 2011, the under-five mortality reached 80.2 per 1,000 and 117.4 per 1,000, respectively in Sudan and South Sudan. These levels are 38 and 47 per cent lower than in 1990. conclusion: The proposed child mortality estimates could be useful for policy-makers and organizations active in Sudan and South Sudan as well as informative for the MDG-4 process in both countries. ORIGINAL ARTICLE Under-five mortality estimates for Sudan and South Sudan Thomas Spoorenberg, Ph.D. Associate Population Affairs Officer Population Estimates and Projections Section United Nations Population Division Department of Economic and Social Affairs 2 United Nations Plaza, Room DC2-1908 New York, NY 10017, USA Email: spoorenberg@un.org Tel.: +1-212-963-3214 Fax: +1-212-963-2147 François Pelletier, M.Sc. Chief Mortality Section United Nations Population Division Department of Economic and Social Affairs 2 United Nations Plaza, Room DC2-1970 New York, NY 10017, USA Email: pelletierf@un.org Tel.: +1-212-963-3213 * The views expressed in this paper are those of the authors and do not necessarily reflect the views of the United Nations. Its contents have not been formally edited and cleared by the United Nations. bAckgrOUnd As a part of the Comprehensive Peace Agreement signed in January 2005 and after one of the longest African civil war (1983-2005), the Southern provinces of Sudan (Upper Nile, Jonglei, Unity, Warrap, Northern Bahr El Ghazal, Western Bahr El Ghazal, Lakes, Western Equatoria, Central Equatoria, and Eastern Equatoria) have held from 9 to 15 January 2011 a referendum on the Independence of South Sudan. The results of the poll were unequivocal with an impressive 99.57 per cent of the votes in favour of the secession of the South Sudan from the Northern provinces or Sudan. 1 In this paper, Sudan and South Sudan are used to refer to the new countries that were carved from the former Sudan in July 2011, unless otherwise noted. Sudan refers to the Northern provinces and South Sudan to the Southern provinces that became independent in July 2011. With the independence of South Sudan on 9 July 2011, production of past, present and future demographic estimates for both Sudan and South Sudan in their current geographic settings is needed. Considering that demographic data are a constitutive part of the building-process of a nation and are useful for the assessment and monitoring of the country’s future development as well as the Millennium Development Goals (MDGs), this short paper aims at contributing to these issues by proposing a consistent time series of under-five mortality estimates for both Sudan and South Sudan and making it publicly available. The reduction by two-thirds, between 1990 and 2015, of the under-five mortality rate constitutes one of the eight MDGs that were agreed upon and established following the Millennium Summit in 2000. Progress in the reduction of the under- five mortality rate serves to evaluate consistently and comparatively the countries towards the achievement of MDG-4. According to the most recent data, the under-five mortality rate in Sudan (north