The biggest growth was seen in the likes of MBIE, where spending grew from just over $1m to $5m over that period and the Ministry for Primary Industries where the spend grew from $1.3m to $4.1m
Brown said that realistically the Government would be spending some money on market research, but questioned the size of the spend.
"There is a role to play in terms of government departments and agencies understanding what their customers and the public expect," Brown said.
"The reality is that this Government is addicted to spending. We've seen a significant increase in this type of expenditure and in a cost of living crisis they should be careful about how much spending they are spending on activities like this," Brown said.
Much of the spending could be justified, as Brown said, by agencies trying to understand the efficacy of their policies. MPI's spend went on understanding farmers' experiences with mycoplasma bovis, which the Government wants to eradicate.
The Department of Prime Minister and Cabinet has been regularly surveying people on their feelings about the Covid-19 Response.
Those surveys look at how people are complying with health rules, and how effective health messaging has been.
Covid-19 Response Minister Ayesha Verrall has previously justified those surveys by saying they were part of ensuring the response was effective because they ensured the Government maintained "social licence" for what it was doing.
"Social licence is one of the factors we consider when deciding on Covid-19 Protection Framework settings.
"This research is also used to identify gaps in the provision of public information around Covid-19 and ensure those gaps are addressed," she said.
However, some of the spend has been criticised for being excessively political.
The Covid-19 research has polled levels of trust in Covid-19 influences. This polling includes non-political figures like Dr Ashley Bloomfield, Michael Baker, and the Ministry of Health website - but it also includes politicians like Jacinda Ardern and Chris Hipkins.
The fortunes of those politicians in that poll could be considered useful for political strategy, which would go beyond the strictly public sector remit of public agency polling.
The Government has also been undertaking "social media listening" reports on Covid-19. These are officially non-political but open to the allegation that information gleaned from the reports could be used for political purposes, as they could offer insights about how people feel about the Government, and by extension, the Labour Party.
Another survey, this one commissioned by the Ministry of Housing and Urban Development on progressive home ownership, a policy that failed to gain traction earlier this term.
Brown criticised this, as the progressive home ownership scheme had gone to the election as a Labour manifesto pledge, Labour should have paid for its own research on whether people actually wanted it or whether it would be successful.
That survey, from August last year, questioned 1,024 New Zealanders who did not own their own home for a scheme the Government funded to reach 4,000 households.
As of February this year, just 58 households had taken advantage of the scheme in the 19 months since it was announced in July 2019.
"They've gone to an election with very little policy so they've had to work it out afterwards. Spending money on polling and research is not the right approach," Brown said.
Public Service Minister Chris Hipkins referred questions to the Public Service Commission.
A spokesperson for the Public Service Commission said it had "no specific guidance around survey questions".
"Accountability for expenditure are matters for the relevant agency chief executive," they said.
In 2019, Hipkins asked the Public Service Commissioner Peter Hughes to look into a political neutrality complaint against an Inland Revenue survey question. The survey asked people where they sat on the political spectrum
The review expanded to look across all Public Service agencies and found survey questions asked by the IRD, Stats NZ and the Department of Conservation were not appropriate but not politically motivated.
As a result of that, the Commissioner wrote to all public service chief executives reminding them to specifically vet surveys for neutrality.
The Commissioner also wrote to Carolyn Tremain, who is in charge of Government Procurement, asking her to convey the findings of the report to contractors involved in public survey and polling work.
