Over the last two and a half decades, the number of countries with household survey data on birth registration has risen dramatically – to over 120 1993 2000 2005 59 79 FIGURE 1. Cumulative number of countries with household survey data on birth registration Close to 1 in 4 countries lack sufficient data to monitor SDG target 16.9 FIGURE 2. Proportion of countries with no or insufficient trend data on birth registration, by region No data Insufficient trend data 2010 2019 108 121 50 40 12 14 30 11 20 16 10 0 0 0 Western Europe North America 5 4 West and Central Africa The timeliness of birth registration data varies dramatically. In some instances, the latest source of globally comparable data for a country dates back to 2006, while in others, it is as recent as 2018. Available data indicate the level of birth registration at the time of collection and do not necessarily reflect the current situation. This is particularly relevant in countries affected by recent crises or conflicts. In addition, the results of any recent initiatives, campaigns or investments to improve levels of birth registration may not be reflected in available figures. It is also important to note that figures obtained through surveys and censuses are highly sensitive to the way in which questions are formulated. This is especially true of questions regarding the civil authorities in charge of recording births. Respondents may not always be clear on who these authorities are and may misinterpret notifying a church or village chief of a birth as formal registration. Household surveys generally customize questionnaires by naming the specific national authority responsible for registration. But even then, confusion about the birth registration process may remain. Similarly, questions regarding the possession of a birth certificate may also be the source of erroneous data, 33 21 13 12 South Asia Eastern and Southern Africa 9 24 14 5 Eastern Europe and Central Asia Middle East and North Africa Latin America East Asia and the and the Caribbean Pacific World since respondents may confuse a birth certificate with a health or vaccination card or some other document. To minimize the risk of misreporting, in some household surveys, interviewers who administer the questionnaire ask respondents to show the birth certificate. For these reasons, the data on registration and possession of birth certificates obtained via caregiver reports need to be interpreted with a degree of caution. Finally, national statistics can mask gaps in levels of birth registration among children who are highly vulnerable. They can include children living outside of households, undocumented nationals, refugees and migrants or other groups who are at particular risk of statelessness and of being left behind in the birth registration process. This is often the case in countries plagued by ongoing and protracted crises and neighbouring countries that are dealing with refugees and migrants fleeing conflict and instability. Algeria, for instance, has achieved nearly universal birth registration among children under 5 at the national level, according to the latest available data. But this does not reflect the situation of roughly 21,000 Sahrawi refugee children under age 5 living in camps in the province of Tindouf.25 Progress and challenges in data availability and quality 13