Relations between the politicians and their bureaucrats are so little discussed by the media that I suspect many people still have a Yes, Minister view of what goes on in Canberra: the public servants pretend to be the servants of the politicians, but they're actually the bosses. Government is run by a bunch of Sir Humphreys who manipulate their ministers, pollies who come and go without making much difference. It did indeed work like that in Canberra as well as Whitehall, but that's been becoming less and less true since the 1970s. By now it's the very opposite of the truth. These days, ministers and their private office advisers have most of the power and their departments have surprisingly little. I might have said Treasury was the major exception to the new rule, were it not for the unprecedented disaster of the 2014 budget. No influential Treasury and Finance departments could have handed their political masters such a booby trap. It had to be largely the pollies' and their advisers' own incompetence. The move from Yes, Minister to Be It On Your Own Head, Minister has come in stages, starting with the decision of the Whitlam government to allow ministers a much greater personal staff of (unaccountable) policy advisers and media managers. The Fraser government perpetuated this "reform" with enthusiasm.

The Hawke-Keating government's main contribution was to replace "permanent heads" of departments with department secretaries on five-year contracts. After five years heading one department you'd be moved to heading another. Thirty-odd years of this and now senior bureaucrats rarely stay long in any department, but climb the ladder by moving from department to department. They've gone from being long-experienced experts in particular policy areas to "universal managers". I may not know much about health or finance, but I know how to run a department. Great. It was John Howard who, on coming to government, immediately sacked many department heads. Abbott did the same on a smaller scale, but even sacked the secretary to the Treasury (and his likely successor). Their purpose was not so much to "politicise" the public service as to scare hell out of the other department heads: toe the line, don't give fearless advice. And don't get identified with a controversial policy the other side may take exception to.

The plain fact is the Libs neither like nor trust the public service, the last bastion of the hated union movement. They've largely given up the practice of having many of the jobs in ministers' offices done by people on secondment from their department. They've been replaced by young bossyboots hoping for a career in politics, who know more about partisanship than policy and are more inclined to listen to lobbyists. Add to this the annual, deeper, across-the-board cuts in departmental budgets – ironically known as "efficiency dividends" – and you end up making many policy experts and repositories of corporate memory redundant. The result is that many departments are weak on policy – there was a time when officers in Finance knew where each department's bodies were buried – and have to call in expensive consultants, who act like they know more than they do. The part of Treasury responsible for tax reform has lost a third of its staff. Last year's budget and the fate of its progenitors stand as a lasting monument to the folly of running down the bureaucracy's policy-making capacity and limiting its role in policy formation in favour of young amateurs with a party pedigree.