A birth is characterized by the creation of a combination of production factors with the restriction that no other enterprises are involved in the event. Births do not include creation of entries into the population due to mergers, break-ups, split-off or restructuring of a set of enterprises. It does not include entries into a sub population resulting only from a change of activity. A birth means the enterprise starts from scratch and actually starts activity. An enterprise creation can be considered as an enterprise birth if new production factors, in particular new jobs, are created. If a dormant unit is reactivated within two years, this event is not considered a birth.