The latest South African Census, released this week, is a hugely important set of numbers that will be used to shape policy and budgets. But is it accurate enough?

Three experts expressed concern to Daily Maverick this week about the extent of the undercount of the just-released Census 2022. The undercount refers to the proportion of the population who were missed during counting.

For Census 2022, that figure is 31%.

The experts, who did not wish to be named, stressed that a fuller picture of what happened would be available only once the relevant Census data has been worked through. But the undercount figure of 31% is considered a significant cause for alarm.

The previous closest contender was in 2001 when the undercount was at 17% - a figure former Statistician-General Pali Lehohla would later characterise as Stats SA having "lost the plot".

For Census 2012, the undercount of 14.6% was considered a concern - particularly because the previous year, Lehohla had promised that the double-digit undercount would be a "thing of the past".

In this latest census, the undercount has more than doubled.

In developed countries, the census undercount usually hovers around one to 2%. Different countries employ different methodologies to calculate the undercount, so direct comparisons are difficult, but research suggests that the average in African countries is less than 5%.

Stats SA bullish,...