If you think Scott Morrisons been busy doing not very much since the election in May, you are much mistaken. In truth hes been very busy doing stuff of not much interest to you. But sometimes it pays to take an interest in things that dont seem of interest.

For instance, I wouldnt expect you to have taken much interest in the reshuffle of government departments he announced on Friday. But Ive been reading up on it and been amazed or appalled by what Ive learnt.

Scott Morrison has revealed four departments will go and five secretaries will lose their jobs in a shake up of the public service.

Its said to be the most dramatic overhaul of the federal public service since 1987, cutting the number of departments from 18 to 14 while creating four new mega-departments and removing five departmental secretaries, three of them women.

Morrison said it was not a cost-saving measure, but had been done to better align and bring together functions within the public service so they can all do their jobs more effectively and help more Australians.

So be very clear on that: its been done to ensure you and I get better service from the public service. Specifically, the number of departments was shrunk so as to ensure the services that Australians rely on are delivered more efficiently and effectively.

I just have one problem: thats what they all say. If Morrison had increased rather than decreased the number of departments, he would still have assured us it would make the public service more efficient and effective.

This is hardly the first time departmental arrangements have been changed. Theyre changed after every election and often several times more. Changes are so common bureaucrats have a name for them: MoG changes in the machinery of government.

According to calculations by Bob McMullan, former Labor minister turned academic, more than 200 changes have been made since 1993-94. In 2015-16, machinery of government changes involved the movement of 8000 staff in 21 separate changes. Changes following the 2013 election, which involved the movement of 12,000 staff, cost an average of $14 million per agency.

Governments everywhere do it, but research by academics at UNSWs Canberra campus suggests Australian governments do it far more than others. Even governments with an emphasis on cutting red tape [such as this one] have undertaken extreme and costly MoG changes, they say.

So why are the latest changes said to be the biggest since 1987? Because thats when the Hawke government introduced the idea of merging departments into mega-departments. Paul Keating reversed some of those changes and John Howard undid much of the rest. Get it? Its time to mega up again.

When the changes cause the name of some function to drop out of the ever-longer titles of departments, the interest group invariably sees red. A few years ago it was the scientists, this time its the arts. Actually, the arts have never had their own department, but have been shunted from one department to another.

Since Bob Hawkes day theyve gone from Environment to Communications, back to Environment, then Regional Development, Prime Minister and Cabinet, back to Regional Development, then Attorney-Generals, back to Communications and now to the new mega Department of Infrastructure, Transport, Regional Development and Communications.

So many MoG changes involve moving functions from one department to another that McMullan has christened them merry-go-round decisions. Responsibility for childcare, aged care and Indigenous affairs (to name a few) have all been the subject of multiple shifts in the past decade. In some cases, the functions have moved out of one department only to return to their original home a few years later, he says.

He adds that disentangling financial structures, IT support structures, property responsibilities and HR systems from old organisations and reintegrating them into new ones takes considerable time and effort.

Former boss of Prime Ministers Terry Morans comment on the latest changes is blunter: Therell be turmoil in many departments for a significant period."

So why do the changes keep happening? Partly to create the appearance of progress reform. Sometimes I think the pollies are trying to convince themselves as much as us. But mainly to indulge the preferences, prejudices and professed priorities of the prime minister and his or her ministers.

Its notable that these extensive changes to the bureaucracy including the sacking of five department heads involve no changes to the ministry. The new mega Department of Agriculture, Water and the Environment will now contain three Cabinet ministers, co-equal in power and glory.

What particular preferences and prejudices of Morrison do the latest changes reveal? I think it reveals this governments disdain for public servants. Its the revenge of the ministerial staffers (which many ministers started their political careers as). Who needs public servants giving ministers advice when its the staffers who understand the politics of the matter?

This is Morrison surrounding himself with the top public servants he knows and likes, replacing the ones who want to keep talking about policy with can-do men and women who dont argue.

Morrison has repeatedly expressed his belief that he doesnt need policy advice from public servants. They should just be getting on with implementing the policies the government gives them. I think this is Morrison perfecting the hermetic seal of his personal Canberra bubble. He already knows whats on his to-do list and he doesnt want news from the outside world delaying or deterring him from his purpose.

Ross Gittins is the_Heralds_economics editor.