Should I use enumerated data, usual residence data or estimated resident population?

Should I use enumerated data, usual residence data or estimated resident population?

At .id, we are excited about the upcoming releases of 2016 Australian Census data #datanerds. To help you make the most out of the new data when it lands, we are putting together a series of blogs to guide you through the nuts and bolts of Census information. First up, we look at what the difference is between enumerated data, usual residence and estimated resident population to help you understand when to use each type of data.

So, what’s the difference between enumerated, usual residence and estimated resident population?

Here’s a quick description of each type of data:

  • Enumerated data set – a count of where people were on Census night.
  • Usual Residence data set – records where people usually live based on Census night.
  • Estimated Resident Population (ERP) - the official ABS estimate of the Australian population. While based on results of the Census, it is updated yearly and includes adjustments for Census undercounts and people overseas.

Census in Australia is collected on a “place of enumeration” basis. This means that wherever you’re staying on Census night, that’s where you fill in a form and are counted. This is the best way of ensuring everyone is counted.

Since the early 1980s however, the Australian Census form has also asked “Where was the person’s usual address?”, which is to be filled in for people to be counted away from home. 95% of people are counted at home anyway, so we are only talking about tinkering around the edges here. The advent of address coding in the early 2000s made it feasible to put people back in their Census Collection District of usual residence, and in 2006 this was made the standard output method for ABS. So if you are a council planning services for your local government area, Usual Residence would likely be the figure you’d use! Here at .id we’ve also moved to this as standard, but we still have the enumerated population available, for those who want a Census-night count, and to compare back to the Census years 1996 and 1991, when Usual Residence is not available for small area geographies.

Here’s a summary of the differences between Enumerated population and Usual residence population:
Enumerated population Usual residence population
  • A point in time (Tuesday night in August) – Census night population
  • Address where people usually live or have lived recently (6 months or more)
  • Available for all years back to 1991
  • Available 2001 onwards
  • Available for all person, dwelling and household topics (but household information still uses some data on people temporarily absent).
  • Available for person datasets only
  • Useful for holiday areas, estimates of services to a winter weekday population.
  • Useful for all services which use the locally resident population.
  • Example question: How many visitors were staying in Surfers Paradise on Census night?
  • Example question: What is the age structure of the people who live in this area?
  • Formerly standard dataset for 2001 and earlier Censuses.
  • Standard dataset for ABS Census from 2006 onwards and, 2001 onwards. now gives users the option to select from comparison years in either Enumerated or Usual Residence datasets, and makes it clear which years are available for each.

However, even Census data at usual residence level isn’t a perfect record of who lives in an area. There may be Australian residents who are not counted due to a myriad of reasons (eg. dwellings missed by a Census collector, incorrectly excluded from a form and assumed counted elsewhere etc.). The estimated resident population includes adjustments to account for these Census undercounts as well as people overseas on Census night who are not required to fill in the Census. The ERP is then updated annually against births, deaths, internal and overseas migration data to provide holistic view on how Australia’s population changing. It also means we don’t have to wait every five years for the population figures! In saying that, Census information forms the base data for these ERPs – and you will be surprised at how estimations can go quite wrong in five years (i.e. the 2011 Census data showed previous population estimates were too high).

Your guide to using this population data:
  • If you want to know the characteristics of people who are resident in an area, use the Usual Residence population.
  • If you want to know the characteristics of people who were in an area on Census night (eg. a tourist area), or want to compare change back to Censuses pre-2001, use Enumerated.
  • If you just want to know the current or past population of an area, use the Estimated Resident Population (updated annually).

Here’s a video to help you better understand these population counts:

.id is a team of demographers, population forecasters, spatial planners, urban economists, and data experts who use a unique combination of online tools and consulting to help governments and organisations understand their local areas. Access our free demographic resources here.

Glenn - The Census Expert

Glenn is our resident Census expert. After ten years working at the ABS, Glenn's deep knowledge of the Census has been a crucial input in the development of our community profiles. These tools help everyday people uncover the rich and important stories about our communities that are often hidden deep in the Census data. Glenn is also our most prolific blogger - if you're reading this, you've just finished reading one of his blogs. Take a quick look at the front page of our blog and you'll no doubt find more of Glenn's latest work. As a client manager, Glenn travels the country giving sought-after briefings to councils and communities (these are also great opportunities for Glenn to tend to his rankings in Geolocation games such as Munzee and Geocaching).

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