Public servants beware - zombies are coming! Not screen zombies - although we've seen plenty of them over Halloween - but policy zombies.

These are more frightening: a menace to planning, budgets and good governance. A zombie policy is an idea long ago killed off by evidence but which refuses to lie down and die. It eats the brains of gullible commentators, newspaper letter writers, lobby groups and citizens. Sometimes it even stumbles into a minister's office and eats an adviser's brain.

A few years back Queensland University economist John Quiggin wrote a book Zombie Economics, about economic policy zombies. They include beliefs that markets can solve any public policy problem, prices always reflect the value of investments, or making the rich richer will help wealth trickle down to everyone. Although empirical evidence has killed these notions stone dead, they are still advocated by many in Western governments.

Fortunately zombie economic policies are becoming easier to spot - perhaps why fewer are roaming Australia today. But don't relax; economic zombies are not all gone, and others are rising in industry, energy, welfare and environment policy. They are a danger to us all.

Drought is a bad time for zombie policies, including the idea of "drought proofing" (impossible - we cannot avoid droughts in Australia) and subsidies for freight and fodder. Subsidies don't help farmers - they increase prices, often go to the wrong people, increase land prices so making farming more expensive than it should be, and discourage farmers from preparing for drought.

Drought zombies thrived for the 80 years following the massive Federation drought but were killed off by, among other things, removal of drought from natural disaster relief in the late 1980s (drought is not an unexpected disaster, it is a recurrent event in Australia), a national Drought Policy Review and a well developed national policy based on evidence.

Sadly, the policy was abandoned when times improved. Now, as the National Farmers Federation - admirably opposed to zombies - has observed, we need to bring back a national policy based on preparedness, sustainability, resilience and risk management. It seems the present generation at the federation have not had their brains eaten by subsidy zombies: a good thing for policy.

One of the most dangerous of the re-awakened zombies is the Bradfield Scheme. This 80-year-old scheme to turn Queensland rivers inland has been debunked by evidence numerous times, including from the CSIRO and the Bureau of Meteorology Research. It would be horribly expensive, a potential ecological disaster, and won't work. Long dead, yet still won't die. It has such persistence that maybe it's not even a zombie but a vampire with the mental powers to enthral weak-minded humans.

The field of innovation is full of zombies from old policy graveyards. Innovation expert Roy Green of UTS once estimated that Australia had had 60 reports on innovation in just 15 years, and is scathing about the most recent versions. Although innovation is key to future prosperity, our policies are not effective. Innovation policies keep being recycled, including those that don't work.

So-called clean coal is another policy with little chance of delivering. It involves high costs and raised expectations that will not be met. Despite this, it still has adherents. In fact, there are many zombie energy policies. In the absence of an overarching energy plan for Australia, smaller policy zombies thrive. For example (crossing over to another horror movie genre) a recent Australian Financial Review opinion piece called the Queensland government's approach a "political Frankenstein" - another monster policy to terrify unwary citizens. The undead don't respect federal-state relations or political lines, they infest states and territories as much as the Commonwealth, and attack both Labor and Coalition governments.

They can be found everywhere, including in the remotest parts of the country. Aboriginal and Torres Strait Islander policy advisers who advocate community gardens are promoting zombies. These sound nice but don't work: in some communities there are visible signs of successive failed gardens in the same plots. Policies like these can work if they emerge from communities, but when imposed from outside they struggle.

Some policy zombies are not stirring, but rest in shallow graves: conscription, capital punishment, WA secession, protectionism, underarm bowling against New Zealand. It would not take much for them to dig themselves out and attack good policy.

It's a horror movie out there. The Thodey review has still not become public - it's the Poltergeist of the public service, disturbing but never seen. How can we explain the legion of identikit teenage ministerial advisers under the Rudd government as anything other than Midwich cuckoos (for movie versions see Village of the Damned), with supernatural mind control, allowing them to bend humans to their will? Are ministerial advisers today still human? What if some of them are controlled by an alien intelligence (The Puppet Masters), or aliens mimicking humans? When their objective appears to be world (or at least Australian political) domination, it can be hard for a poor public servant to tell. If you receive an inexplicable instruction from an adviser, think of Invasion of the Bodysnatchers. Be very afraid.

What are public servants to do? Remember the rules from Zombieland. OK, not all 32 from the first movie or 52 from the second. Just some of the important ones:

Double tap: if presented with a zombie policy, find evidence to kill it and brief your minister not once but often. In fact, provide a good hit of evidence to kill it off (again) every time it reappears - you cannot assume previous briefings hit the mark.

Buckle up: keep yourself safe by doing your own work as best you know how.

Always know your way out: if you see a zombie policy, have a well prepared policy alternative to offer. Another pathway may be the best answer.

Finally, don't be afraid to ask for help: work collaboratively with your colleagues and you just might have a chance.