Methods

• Census: Done every 10 years and legally has to be filled out. Households complete a detailed questionnaire about the number of people living in their home
• Census: Also some questions about social, economic or cultural background. Expensive and population changes in the time in between
• Civil registration: Registers all births and deaths. Up to date data in between census'
• Scottish household survey: Continuous survey based on a random sample of the population (about 10,000 households per year). Cheaper than a full census. Voluntary - no legalities. An interview following the main survey
• Government: Migrant data via visa applications - to find a rough estimate of the number of people migrating into the country
• Government: NHS health data also to help gather information on the total population