Dr Gruen is a well regarded macroeconomist and bureaucrat who was a key member of the Treasury team that advised the Rudd Government on its response to the global financial crisis.

From Treasury he moved to the Department of Prime Minister and Cabinet, where he has served as a deputy secretary with responsibility for G20 and the economy.

Treasurer Josh Frydenberg said Dr Gruen was a highly experienced bureaucrat who had a "demonstrated track record of leadership in public policy and outstanding economic and international credentials".

"The skills and experience Dr Gruen will bring to the position will ensure the ABS continues to be responsive to community, business and government needs for data, statistics and insights," Mr Frydenberg said.

Dr Gruen, who takes up the five-year appointment on December 11, comes to position at a difficult time for the agency.

Mr Kalisch used his final public address as Australian Statistician to warn that ballooning data security costs were eating into the ABS's ability to produce vital reports on the economy and society.

In a speech to the Institute of Public Administration Australia on November 28, the statistician said that technological advances had enabled the agency to make much greater use of the information it produced.

But, in a veiled swipe at the Federal Government's tight financial constraints, Mr Kalisch said the cost of protecting this data was rising, reducing the amount that could be devoted to gathering and producing statistics.

"Technology is not just an enabler, but a source of vulnerability for both operations and reputations," the chief statistician said. "Overall, ABS is having to devote more of our scarce resource to regularly enhance our physical data security, but this does reduce resources available for statistical production."

Earlier this year the ABS reported a 30 per cent cut in real terms to its operational funding in the past decade, coinciding with rising data collection costs and increasing demand for information.

At the time, Mr Kalisch said this "conundrum" had forced the statistics agency to pare back some of its operations.

"While ABS is more efficient and effective than it was previously, funding cuts of this level inevitably reduce the service we can provide for governments, businesses and the community," he said in the agency's annual report.

"Our economic, labour market and population statistics have been prioritised, and are consuming an increasing share of our budget funding. These will now be the statistics at risk if there are further cuts to ABS funding over future years."

A low-point of Mr Kalisch's term as chief statistician came in 2016 when people threatened to boycott the census over data privacy concerns, and then the census website crashed.

"I have never experienced anything like the media, social media and political response to the 2016 Census, until it happened," he said, and advised the audience, mainly comprising public servants, that "you need to maintain perspective, integrity and authenticity while the maelstrom is at its peak".

But he insisted that the census that year was a success.

"I still get angry when people refer to #Censusfail, because it didn't.

"ABS and the community response ensured that the 2016 Census succeeded."