A report into “lessons learned” from Scotland’s last census will be completed by the end of this year, National Records of Scotland (NRS) has said.
Last year Audit Scotland called on the archives agency to establish why Scotland’s initial return rate was lower than other parts of the UK.
Concerns about an initial return rate of 79% saw the 2022 census extended by a month, increasing the rate to 89% at an additional cost of £6m.
NRS was responding to a statement from the Scottish Liberal Democrats, who hit out at the cost of the census, which has an overall budget of £144.6m.
MSP Willie Rennie said: “The auditor general warned that this led to increased costs and additional work.
“Taxpayers have ended up paying far more for fewer people to respond.
“Ministers made significant changes including moving the census online and getting out of sync with data collection elsewhere in the UK.
“Then they refused to learn any lessons out of nationalistic belligerence.”
The Lib Dems said the “botched” census would impact the delivery of government services over the coming years.
Officials have previously said that robust data can still be produced from the census, despite not reaching the target of 90%.
An NRS spokeswoman said: “No other survey provides the range of information that the census does.
“Estimates from censuses elsewhere have shown that every £1 spent on census returns around £5 in economic benefit.
“Whilst much of the costs of the census are focused on key delivery years, most long-term benefits are felt throughout the extended programme life cycle, after the collection phases.
“NRS has continued to ensure we only spend what we need to deliver a census and its associated benefits. Where efficiencies can be made, they have been to ensure we maintain value for public money.
“An evaluation of Scotland’s census 2022, with a focus on lessons learned for any future census and other complex programmes, will be prepared for ministers and provided to parliament by the end of 2024.”
She continued: “89% of responses were received via the online platform and 11% via paper form.
“This split is the same as that seen in the 2021 England and Wales Census.”