Midtårsbefolkningen

Midtårsbefolkningen, or the mid-year population, is a demographic concept referring to the number of people living in a country, region, or municipality at the middle of the calendar year, typically around 30 June or 1 July. It provides a stable reference point for annual statistical indicators and cross-year comparisons.

The mid-year population is used as the denominator in a wide range of measures, such as birth and death rates, migration balances, and age- and sex-specific indicators. It also informs planning in areas like public health, education, housing, and labor markets, and supports international comparisons where consistent population baselines are needed.

Calculation and data sources often involve combining census counts, civil registration data on births and deaths, and migration records. Many statistical agencies publish official mid-year population estimates for each year, sometimes supplemented by statistical models to account for delays or gaps in administrative data. Because it is an estimate that integrates multiple data sources, the mid-year figure may differ from year-end or other date-specific counts.

Relation to other measures: the mid-year population is distinct from the population at a fixed date (such as year-end) and from point-in-time counts taken for other administrative purposes. Differences between mid-year and other measures reflect varying timing of births, deaths, and net migration within the year.

Limitations include methodological differences across countries and revisions as new data become available. The concept is widely used in national statistics to provide a consistent, comparable basis for demographic analysis.