Policy without the Hot Air

Be honest about uncertainty. Be data led. Build something, iteratively. And make it open.

David MacKay, former Chief Scientist at the Department of Energy and Climate Change (DECC), died in April. He was only 48.

Many Ministers and senior officials sent their condolences. David owed Whitehall nothing; he gave five years of redoubtable service. Private Eye doesn’t fall over itself to give praise to public officials; it spoke of him in glowing terms before and after his death (indeed, his passing finally put paid to the rumours that he was the magazine’s energy correspondent ‘Old Sparky’).

But the government owes David an appraisal of what he left behind. His death would only be sadder if future administrations failed to heed what he taught. Be honest about uncertainty. Be data led. Build something, iteratively. And make it open.


David joined the Civil Service on the strength of a book. Sustainable Energy without the Hot Air brought clarity to a woolly topic. Energy is a field full of interest groups of all stripes; advocates spanning verdant green to inky black. His engineer’s mind turned the complexity and cant into an elegant story based on evidence. And like the best academic minds, David explained his thinking with concision and power.

After joining DECC, David pushed for the department to build a simple tool that would allow users to pick from the full spectrum of physically possible choices for the future supply and demand of energy — the number of nukes, the miles we travel, and so on. Ministers and officials could see how close their choices would get them to reaching the UK target’s of reducing CO2 emissions by 80% in 2050 (from 2008 levels).

Fancy building only offshore wind turbines? Want to keep thermostats locked on 21C all year round? Don’t want to cut back on short-haul flights, but happy to turn the lights off when you leave a room? Fine. But here are the consequences of those decisions. Here’s how much space all those solar panels take up. Here’s how far short you are in alleviating climate change if you don’t deal with housing. Here’s how hard it really is.

The point of the Calculator, as David saw it, was not to identify a ‘right answer’ to climate change, security of supply or energy bills. There isn’t one. It was to cut the crap and improve the quality of advice. For any policy or service, there’s more than enough arguments to have without wasting time on rebutting things already shown to be impossible.

Some civil servants resented David and his philosophy. At the time, a large part of the department was organised in to teams that worked on particular energy sources (wave and tidal, nuclear, carbon capture and storage, and so on). This turned teams in to internal lobbying units. At a stroke, the Calculator showed — with real data — that a lot of official time was spent fossicking about with technologies that delivered little more than rounding errors. David’s insistence on using substantiated numbers was seen as almost underhand; in some way missing the point. ‘We know you’re wrong,’ aggrieved officials would say, ‘but we don’t have time to find data to prove it. We’re too busy writing the policy.’

Even if the Calculator had been built and left in the confines of Whitehall, David would have demonstrated a policy making model with greater honesty about the complexity inherent to questions that ministers face.

Faced with framing tricky decisions, Whitehall often prefers to construct false certainty rather than engage properly with uncertainty. The traditional paper submission to Ministers must maintain the pretence that the world and everything in it can be boiled down to a shortlist of options. Ministers value terse communications, but civil servants generally feel intellectually short-changed acquiring all this learning only to offer a binary option. So Minsters are instead invariably presented with three or four choices, and given a recommendation to pick Option 2 (it tends to be Option 2). David and the team built something that was easier to absorb than a submission, and gave Ministers millions of options. Presenting the choices for a future energy system in any other way— indeed, framing almost any big decision a government has to make — is usually a white lie.


There has been plenty of wind in and around government over the last five years about how policy making must evolve to meet the demands of new technologies, wicked problems and an increasingly complex world. Much has been written about ‘policy making in a digital age’ and‘open policy making’. GDS and digital units in departments have made progress in changing how the some parts of the government think about designing services. But we have barely touched the sides of the policy world. For the 20,000 or so civil servants who work in ‘policy’, little of substance has changed for years. Meanwhile, David was quietly proving that an alternative can work.

Be honest about uncertainty. Be data led. Build something, iteratively. And make it open.

Because the other important thing about the 2050 Calculator is that it was published. Here it is, in fact. I‘ve linked to the ‘classic’ version of the Calculator in this article, because since then well-meaning officials have created a pretty but less usable update.


What should Whitehall take from David’s legacy?

First, there’s the people he had at his disposal. The freedom to build the right team for the task was vital. Brilliant as he was, David couldn’t have done this on his own. The team that he and others created to build the Calculator was a series of happy and fortunate accidents. The team included an ex-BCG consultant, a superb techie, a Cambridge engineering post-doc, great Fast Stream graduates. He had Director-level peers with Whitehall cunning that David lacked. (It had me on it too, as ballast.) DECC was a young, enthusiastic department. This was a diversity of talent that came from deliberately hiring outside the standard Civil Service guidelines. This was not a standard Whitehall team. But there wasn’t a contractor in sight. They weren’t needed.

Second, there was his standards. David hated sloppiness. Being red penned by him was a rite of passage many of us for whom writing bureaucratic crapulence was like falling off a log. I remember many papers of mine returned festooned with exclamation marks, margin calculations checking my errant numbers, complaints about the absence of sources. With the self-confidence of the very smart, David knew that if he didn’t understand a sentence, or a number or a stock image selection, there was a 99% chance that was because it was bullshit. And he called it out. Every time. We learned. David made more people better civil servants with minutes of his time than thousands of classroom hours ever have. Civil servants can, should and must learn much more from experts like him.

But the most important thing the government should take from David’s pet project is that it worked. The 2050 Calculator — and the approach David took in building it — made the UK’s energy policy substantively better. It protected us from rash guesswork in a crisis, as could have easily happened in the aftermath of the Fukushima nuclear disaster (and actually did in Germany). It prepared us for giving more thoughtful answers to long-term questions, as when it helped set the legal emissions targets of the fourth carbon budget, covering a period that was 15 years hence at the time.

One of the most recognisable recent efforts to ape the 2050 Calculator approach was produced not by civil servants but by Ben Goldacre and Anna Powell-Smith on the OpenPrescribing project. They did brilliant, cost-effective work, publishing anonymised data about the drugs prescribed by GPs in England. It cost very little. Why did the government not get there first? And can work by outsiders ever have the impact the Calculator did? Who knows. But they were — I’ll say it again — open, iterative, data led and honest about complexity.

As time passes, I feel like I learn more from the experience of working with David. Let’s hope the same is true of government.

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