7.4 Cohort - a group experiencing the same event

Cohort refers to a group who experience a certain similar event at a specific time. For example, a birth cohort is a group born at a certain time (of a year or a longer period). Those born in Finland in 1947 form a birth year cohort. A group of people getting married in a specific year form a marriage cohort.

In Finland we often talk about the so-called large age groups, baby boomers, born between 1946 and 1950. In those years more children were born than during any other five-year period. The large age groups form a cohort whose development has been followed and will be followed for a long time.

Examination of cohorts is most common in connection with fertility, mortality and divorces.