How to Find Undercount in Census

The census taker's job is to accurately report data about households in his region.

The census is a systematic way of counting and collecting data about the population of a nation, state or region, such as race, income, family size and occupation. Obtaining accurate census data is important when it comes time for policy-makers to decide how to allocate funds. If a segment of the population is not adequately represented in the census, their needs will not be met. Because the census cannot be 100 percent accurate, ways to account for undercounting have been devised to more accurately estimate the demographics of the population being surveyed.

Instructions

1. Send a Post-Enumeration Survey (PES) or interview, in person or by phone, a large sample of the population. The population that is surveyed should fall across all income brackets and levels of urban-ness. This will help to account for any people who were not counted in, or did not reply to, the census.

2. Calculate your adjustment factor by checking how many of the people responding to the PES had already been included in the census. The percentage of respondents who had already been counted is your adjustment factor.

3. Re-estimate the population by multiplying your adjustment factor by the number of people in the original census count.

4. Find the undercount rate by subtracting the original census count from the new population estimate you found in Step 3.

Tips & Warnings

• Undercount is more likely to occur among poor, rural populations and populations who do not speak the main language of a country, because of difficulties of communication and access.

References

• Calculation of Undercount: Calculating the Undercount in Census of '96

Resources

• How Do We Know There Is An Undercount?
• Determine Extent of Census Undercounting Among Certain Rural Creek Indians of Oklahoma