Since 1850, the Swiss population is being counted every ten years, with this rhythm only broken with the census of 1888 and the one of 1941. The 1836/37 census, mandated by the legislature, is spotty and suffers from considerable statistical defects. This, by the way also pertains to later censuses.

An early publication of the Federal Department of the Interior informs us about the results of the 1850 census; results of subsequent censuses were published in the “Statistical Deliveries” (“Statistische Lieferungen” / “Livraisons statistiques”) and the “Official Statistics of Switzerland” (“Amtliche Statistik der Schweiz” / “Statistique officielle de la Suisse”), respectively.

The first four Swiss national censuses had serious shortcomings, but between 1880 and 1888, survey quality increased dramatically. However, between 1880 and 1888, the variety of data covered also increased, which forced us to employ restrictions. Certain areas of Swiss demographic history were available to us from the Statistical Year Book of Switzerland, though not without some complementing. We also profited from a recently published special study by André Schluchter which is based on the Federal count of 1798.

Each census since 1860 also contains data relating to employment structure. This special aspect of population development is covered in the “Occupations” chapter.
It should be mentioned that this chapter assigns a certain priority to the presentation of regional differences. Population data on age, gender, civil status, origin, religion, and primary language is given for individual cantons as well as for ten large and medium sized cities (Zurich, Basle, Geneva, Berne, Lausanne, St. Gall, Winterthur, Lucerne, Biel/Bienne, and La Chaux-de-Fonds).

The reason why certain tables in this chapter appear incomplete and inconsistent can be found in the frequent changes in the way the census was performed. In the area of religious belief, especially, the Federal Statistical Bureau never managed to develop a consistent and enduring scheme. Another problem is the varying degree of accuracy with which each census covered the presence of resident aliens; the number of nations of origin varies from census to census.

However, this is not the place for a detailed critique of source data; such a review is a task to be undertaken within the context of a monograph of the Swiss population of the 19th and early 20th century.