Statistics based on personal identifiers
In the meantime reliable alternative sources had become available for the census tables. These consisted in existing registers and administrations, such as the municipal population register and tax and social security registers. The data extracted from these sources were supplemented with data from sample surveys.
New means of communication – computers and the internet – meant door-to-door surveys were no longer necessary. It is the irony of history: with the aid of a personal identifier – the citizen service number, it was now possible to link registrations and survey data to a system of combined datasets, from which census data can be drawn. CBS could do this at any given time.