QUICK GUIDE 5 - KEY QUANTITATIVE METHODS QUICK GUIDE 5 - KEY QUANTITATIVE METHODS Census A census is a full count of all households and individuals in a specific geographic location at a specific moment in time, either in the place they are found at the time that the census is undertaken or at their usual place of residence. The official national population and housing census (official census) is the most common source of population data. Official censuses are usually conducted by governments every ten years, depending on the country. The major advantages of an official census is that it covers the entire population of a country at the time it is conducted, that it uses a well-tested methodology, and that it can provide a comprehensive sampling frame. This is important when measuring statelessness, since stateless persons tend to constitute a relatively small proportion of the total population and may be dispersed throughout the country, making it difficult to reach sufficient numbers of them with sample surveys. An official census can provide valuable information on the size and profile of stateless populations and thereby facilitate the work of policy makers by pointing to potential causes of statelessness and therefore how it can be prevented and reduced once it has occurred. It can also provide quantifiable evidence of the existence of stateless people, where without such data it may have been easier for the Government to deny the problem and thereby fail to take constructive steps to address it. 44 U N H C R > R E S E A R C H I N G S TAT E L E S S N E S S - Q U I C K G U I D E S It should be noted that obtaining statistical data through an official census is not a fool-proof method to acquire accurate information on the extent of statelessness in the country. Official censuses are taken fairly infrequently, usually only every ten years, and it may take several years before detailed statistics become available. Thus, official census data can become outdated quite quickly. Answers given by respondents to the enumerators are self-reported. As individuals may not know whether or not they are in fact stateless and there is little room for enumerators to probe and investigate further, the results may not be reliable. The long form of a census, which is a more detailed census questionnaire that only a random sample of the enumerated population receives, can provide an opportunity to include more detailed questions on nationality and statelessness. If there are statelessness issues in the country and it has an official census coming up in the next 2 or 3 years which does not contain specific questions related to nationality or statelessness, it is recommended to consider using this opportunity to collect statistics on stateless persons in the country. The official census is normally conducted by the National Statistical Office and overseen by a national planning committee which includes the main stakeholders. A special Official Census law is often adopted for each census, and it is a good idea to obtain a copy of and review such laws to understand the scope and any limitations placed on the census. U N H C R > R E S E A R C H I N G S TAT E L E S S N E S S - Q U I C K G U I D E S 45