Traditional census taking

In England and Wales, Scotland, Northern Ireland and 13 other countries in Europe, the householder receives a questionnaire in the post, completes it, and either submits it online or sends it back in the post. In other countries, such as Ireland, a large field force visits every household in the land to deliver, and then collect, census questionnaires. All the countries of Eastern Europe carry out interview censuses, where the enumerators collect and record the information on the householder’s behalf.

As the population grows and changes, censuses become harder to carry out. To get questionnaires out and back faster, many countries are switching from hand delivery and collection to the post. In 2011, thirteen European countries included the option to complete their census forms online.

Though simple, the traditional approach needs to mobilise vast resources to make the census happen and encourage people to take part. Most of the action is concentrated into a matter of weeks or months, supported by a large, temporary field force. Its success depends on winning public support, which is why the 2011 Census for England and Wales was publicised through national, regional and local advertising, public and press relations, and wide local authority and public engagement.

Rolling census

A rolling census takes the census in the traditional way, but to a rolling schedule, taking field counts in every municipality and neighbourhood over five years. Census results are based on moving averages worked out over the five-year cycle and updated every year. The method enables census data to be released more frequently and spreads costs and human involvement over time. France has run a rolling census since 2004.

Short forms

Two approaches to collecting census data enable the majority of the population to complete a short form containing basic information, with more detailed information gathered by means of an annual survey or long form.

Short form with annual survey

Every householder completes a short form – for the US 2010 Census it was just ten questions. A national annual survey is used to update the information and add more detail in the way of population characteristics.

Long form and short form

All households and communal establishment residents have a short form to complete, while a sample of the population has a long form to collect more detail. The short form is used for the population count and to collect basic information such as usual address, sex, age and relationships to other household members.

While this can widen the range of content without asking everyone to complete a long form, it may complicate field operations and limit outputs for small geographic areas. Many years from now, it could also limit the information available to family historians.