migration, and reason for movement including asylum/refugee protection (or conflict-induced internal migration) (UNHCR 2016), or a specific question to identify IDPs or refugees. However, not all censuses cover refugees and asylum-seekers (if foreigners are considered outside the scope of the census or because they are considered a special category),<sup>71</sup> nor is it common practice for national censuses to include questions related to forced displacement.<sup>72</sup> Nevertheless, there are several examples of national censuses that have included relevant questions on forced displacement.<sup>73,74</sup> In the case of protracted internal displacement situations, IDPs are likely to be included in national censuses; however, census instruments may be subject to manipulation for political purposes.

There are several drawbacks of population censuses including their cost, the significant training required for enumerators to ensure consistent answers to questions on forced displacement, impediments to field operations and data processing (such as weather conditions and technical problems), the relative infrequency with which they are carried out, and the long processing time before data and statistics become available, which have consequences for the timeliness of data. Moreover, often censuses are not conducted in contested territory or conflict zones where many displaced persons reside, and this limits the completeness of the data. Nevertheless, censuses are the only nation-wide source of population data for potentially providing estimates of displaced populations, especially those in non-camp settings, and often provide a basis for sampling frames for survey instruments (UNHCR 2016). Capturing displacement situations in official statistics also increases their visibility.

# **_Sample surveys_**

Sample surveys can potentially provide a rich source of data on forcibly displaced populations. Compared with censuses and registers, sample surveys allow more detailed questions to be asked about the characteristics and situations of households. If survey instruments identify displaced populations based on individuals’ and households’ self-reported migration history (including patterns and causes) they can enable the disaggregation of detailed data by displacement status (UNSD 2014).

There are opportunities to mainstream forced displacement into international survey instruments, but this has only been done in a handful of cases. Several standardized international sample surveys have been designed for special purposes including the Living Standards Measurement Study (LSMS),<sup>75</sup> Labor Force 71 The UN census recommendations for the 2010 World Population and Housing Census Programme stipulate that refugees and IDPs living in camps should be counted and their numbers disaggregated in population statistics, however there is no requirement to separately distinguish displaced people living outside of camps (UNHCR 2016). The United Nations Economic Commission for Europe’s (UNECE) guidelines include a question on reason for migration, population with a refugee-like background and IDPs as non-core topics/questions (UNHCR 2016).

72 While most countries include questions on country of birth and citizenship, only about 40 percent include a question on year of migration, less than a quarter include a question on reason for international migration, and about a fifth include a question on the reason for internal migration (UNHCR 2016).

73 E.g. Kyrgyz Republic 1999 (refugee status), West Bank and Gaza 2007 (refugee status), Zambia 2000 and 2010 (purpose of stay), Germany 1970 (federal refugee identity card), Greece 2001 (reason for settling in Greece), Sudan and South Sudan 2008 (type of household including IDP and refugee), Liberia 1990 (ever displaced by war since 1990), Uganda 2014 (refugees).

74 UNHCR is collaborating with the Statistics Norway on systematically embedding forcibly displaced peoples in national statistics exercises and collaborates with national authorities and with UNFPA in various countries on the design of census exercises that include refugees, IDPs, returnees and stateless persons.

75 LSMS is a household survey program housed in the Bank's Development Research Group that provides technical assistance to national statistical offices in the design and implementation of multi-topic household surveys covering household behavior, welfare and interactions with government policies. All data gathered through the LSMS is published online in the Bank’s Central Microdata Catalog.