The accuracy of the 2022 Census numbers is giving Statistics SA sleepless nights. As soon as they were released last October, there were worries that they weren’t as accurate as they should be. Census 2022 also has the highest undercount, which is the percentage of people or households not counted, of any post-apartheid census – 31%😬

A census is, primarily, as accurate a count as possible of the number of people in a country at a point in time. It attempts to describe the demographic and socioeconomic characteristics of a country. It also provides estimates of fertility and mortality of the population. Census data can also be used to plan the country’s finances and figure out where to build houses, schools, infrastructure and places of employment. 

Now, we South Africans are no strangers to setting records, but this one is a bit shameful: the undercount set a new international record, some ten percentage points higher than the previous highest notified undercount (in Comoros in 2017).

What happened?

According to University of Cape Town (UCT) Professor Tom Moultrie and UCT Professor Emeritus Rob Dorrington, several factors affected the count:

  • The COVID-19 Pandemic: Attempting to run a census during the COVID-19 pandemic complicated planning and operations. This decision appears to have been forced by the national treasury’s refusal to hold over the budget for the census to the next fiscal year.
  • There were delays in recruiting and training field staff to conduct in-person data collection. The original intent had been to collect as much data as possible from households online using a web portal, but a massive fieldwork operation had to be mounted at short notice.
  • Repeated extensions to the period during which data is collected. This was particularly true in the Western Cape, where enumeration ended nearly four months after the census.
  • Problems with the Post-Enumeration Survey used to derive the adjustments to produce the final population estimates. First, delays in the running of the survey, which involved attempting to match household membership many months after the census date. Second, the scope and size of the survey was far too small to accurately adjust the enumerated population for the undercount identified. Third, there are inexplicable statistical anomalies in the results from the survey and the adjusted census results.

They say that the operational and logistical difficulties encountered in planning and running South Africa’s 2022 census render the data collected unfit for purpose.

What now?

With such a high undercount, Moultrie and Dorrington say that an alternative set of population estimates by age, sex and population group is urgently required. “These alternative estimates may more accurately describe the South African population and provide a better basis for resource allocation and planning,” they wrote. 

Will there be another census? It is highly unlikely. The next one is in 2031, and hopefully, the mistakes of 2022 will be avoided.