ResPublica's study claims that transforming council areas into unitary authorities could result in national savings of billions of pounds and potential gains to the economy in England’s county areas of Â£31 billion over five years.
At the same time, it would mean improvements for Northamptonshire businesses, housebuilding, and public services that are essential to avoid the county becoming "left behind" it says.
Northamptonshire uses the ‘two-tier’ system of local government, which means that it has two separate councils - a county council and smaller district councils.
Respublica says that the "overlapping" of services - where one authority collects rubbish and the other disposes of it for example - is costing taxpayers Â£6 billion each year across the UK.
Phillip Blond, director of ResPublica, said Northamptonshire is a key example of a county in need of local government reform.
He said: “The needless confusion that frustrates the ambitions of business and government alike in our county areas must end now.
"With Brexit on the horizon and our city-regions already benefitting from devolution, we can’t afford the waste and complication that the current system creates. Single councils at the county scale are the future and we call on the Government to move rapidly to encourage them.”
However, the report comes two months after the leader of Northamptonshire County Council, Councillor Heather Smith (Con, Oundle) claimed there was "zero chance" of Northamptonshire becoming a unitary authority before 2020.
As Brexit legislation is set to take up such a large proportion of Parliamentary time between now and 2020, she has been told there will almost certainly not be enough time to hear Northamptonshire's bid for unitary status in the Commons.
She added that council leaders across Northamptonshire are also yet to come to an agreement as to how a unitary authority system would look.
Northampton Borough Council, for example, believes the county should be split into two unitary authorities - one council governing Northampton and another overseeing the rest of the county.
But Respublica believes Northamptonshire could save Â£1.3bn over the next five years by moving to a unitary system in one of two ways.
One plan would see the district councils abolished, with some of their budgets and buildings given to local parish and town councils.
Alternatively, the leaders of the District councils could become a ‘cabinet’ for Northamptonshire County Council, making decisions together.
The report will be launched at the County Council Network’s Annual Conference on Monday, November, 20.
Report author Tom Follett, policy manager for cities and devolution at ResPublica, said: “Central government finds itself struggling to deal with the complexity of the demands placed upon it, hemmed in by limited resources and national difficulties of unprecedented scale.
"Local government offers an alternative but is being called on to take up a role which is unsuited to its current structure and design.
“Adopting these reforms is a matter of urgency. Local government in the counties, as it currently stands, is simply unable to rebalance the economy, or provide the homes we need."