Osborne's dynamic plan

How a technical change in Treasury forecasting could help scrap the 45p tax rate.

At the Treasury Select Committee yesterday, in between being quizzed by MPs angry at the extent of the pre-budget leaks, George Osborne revealed that he was planning to enable the OBR to make greater use of so-called "dynamic scoring" when they prepare their economic forecasts – but only when examining tax plans. It may not sound it, but if he made that change, it would be a huge coup for the right.

Dynamic scoring is the practice of including behavioural changes in economic forecasts. Without it, in a static model, changes to revenue after something like a tax hike are facile to calculate. If VAT at 17.5 per cent takes in (say) £175bn, then VAT at 20 per cent will take in £200bn. Similarly, if you are trying to calculate the effects on government revenues of spending £100m buying new trains for the east coast main line, then you can conclude that it will cost £100m – you buy the new trains, everyone carries on riding the line, and nothing changes.

What a static model says is that people are blind to the effect that government actions have when they are choosing what to do. Clearly, that is untrue. But it is also very easy to calculate, which is why it has stuck around for so long.

Dynamic models include all these changes of behaviour. So when looking at a dynamic model for rail investment, you can take into account the fact that nicer trains will make people more likely to travel, boosting ticket revenue; and when looking at a dynamic model for VAT rises, you bear in mind the fact that as prices rise, people buy fewer things, so that an 11 per cent rise in VAT won't lead to an 11 per cent rise in VAT revenue.

The problem for economists is that dynamic models are a lot harder to calculate. Not only are there far more variables to take into account, but you open yourself up to more avenues of attack from political opponents. The combined effect of all the assumptions you must make means that your conclusions can be deeply flawed if you get too many wrong, and, as the IFS says (pdf), can "[open] the door to large controversies if these guesses are made – or perceived to be made – in a politically biased way." While static models contain assumptions that are obviously false, dynamic models still contain assumptions, which can still be just as false. And unlike static models, we can't know which ones these are until it is too late.

So why does George Osborne want to introduce dynamic scoring into OBR models? Does he believe that the government's economists have uncovered a breakthrough understanding in behavioural responses to government intervention?

A clue can be found in HMRC's report into the 50p tax rate, which found that dropping the rate down to 45p would cost far less than expected, because of expected behavioural changes. Indeed, this sort of dynamic thinking is the cornerstone of the Laffer curve, the economic theory that, past a certain point, increasing tax rates reduces revenues.

What Osborne will be hoping is that allowing the OBR to make its models more dynamic still will strengthen the rationale for scrapping the 45p rate entirely, as well as for cutting corporation tax all the way down to 20p by the end of parliament.

Yet while the OBR will be "informed" by these new dynamic models when it comes to tax policy, they won't be taking account of the same information when examining the justification for government investment, where, far from strengthening Osborne's preferred policy, it would weaken it. If dynamic scoring is indeed implemented in this narrow fashion, Osborne will have scored a stealth victory for future Tory policy.

Money on the mind: A 19th century phrenology chart. Credit: Getty

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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The biggest divide in politics is not left against right, but liberals against authoritarians

My week, including a Lib Dem membership rise, The Avalanches, and why I'm putting pressure on Theresa May over child refugees.

It is a boost for us that Nick Clegg has agreed to return to the front line and be our Brexit spokesperson. I hadn’t even had a chance at our meeting to make him the offer when he said: “Before we start, I’ve been thinking about this and want to take on the fight over Europe.”

With Labour apparently willing to give the Tories a free pass to take us out of Europe, the Liberal Democrats are the only UK-wide party that will go into the next election campaigning to maintain our membership of the EU. The stage is remarkably clear for us to remind Theresa May precisely what she would be risking if we abandon free trade, free movement, environmental protection, workers’ rights and cross-border security co-operation. More than a month on from the referendum, all we have heard from the Tories is that “Brexit means Brexit” – but they have given us no clue that they understand what that means.

 

Premature obituaries

Not long ago, the received wisdom was that all political parties were dying – but lately the supposed corpses have twitched into life. True, many who have joined Labour’s ranks are so hard left that they don’t see winning elections as a primary (or even a desirable) purpose of a party, and opening up Labour to those with a very different agenda could ultimately destroy it.

Our experience has been happier: 20,000 people joined the Liberal Democrat fightback in the wake of the 2015 general election result, and 17,000 more have joined since the referendum. We now have more members than at any time this century.

 

Breaking up is hard to do

Journalists have been asking repeatedly if I want to see the break-up of the Labour Party, with moderates defecting to the Liberal Democrats. I have been clear that I am not a home-wrecker and it is for Labour to determine its own future, just as I focus on advancing the Liberal Democrat cause. Yet I have also been clear that I am happy for my party to be a home for liberals of whatever hue. I enjoyed campaigning in the referendum with a variety of progressive figures, just as moderates from different parties shared platforms in 1975. It struck me that far more unites us than divides us.

That said, not all “moderate” Labour figures could be described as “liberal”, as John Reid demonstrated as Labour home secretary. The modern political divide is less left v right than authoritarian v liberal. Both left and right are looking increasingly authoritarian and outright nasty, with fewer voices prepared to stand up for liberal values.

 

What I did on my holidays

Time off has been virtually non-existent, but I am reading A Wilderness of Mirrors by Mark Meynell (about loss of trust in politics, the media and just about everything). I’m also obsessively listening to Wildflower by the Avalanches, their second album, 16 years after their first. It’s outstanding – almost 60 minutes of intelligently crafted dialogue, samples and epic production.

During the political maelstrom, I have been thinking back to the idyllic few days I spent over half-term on the Scottish island of Colonsay: swimming in the sea with the kids (very cold but strangely exhilarating ­after a decent jog), running and walking. An added bonus is that Colonsay is the smallest island in the world to have its own brewery. I can now heartily recommend it.

 

Preparing for the next fight

The odds are weirdly long on an early general election, but I refuse to be complacent – and not merely because the bookies were so wrong about Brexit. If we have learned one truth about Theresa May as Prime Minister so far, it is that she is utterly ruthless. After her savage cabinet sackings, this is, in effect, a new government. She has refused to go to the country, even though she lectured Gordon Brown on the need to gain the endorsement of the electorate when he replaced Tony Blair. Perhaps she doesn’t care much about legitimacy, but she cares about power.

You can be sure that she will be keeping half an eye on Labour’s leadership election. With Jeremy Corbyn potentially reconfirmed as leader in September against the wishes of three-quarters of his MPs, Mrs May might conclude that she will never have a better chance to increase her narrow majority. Throw in the possibility that the economy worsens next year as Brexit starts to bite, and I rule nothing out.

So, we are already selecting candidates. It is vital that they dig in early. As we are the only party prepared to make the positive case for Europe, such an election would present us with an amazing opportunity.

 

Sitting Priti

David Cameron pledged to take an unspecified number of unaccompanied children from camps across the Continent. I am putting pressure on Theresa May to turn that vague commitment into a proper plan. Having visited such camps, I have been fighting for Britain to give sanctuary to a minimum of 3,000 unaccompanied children, who are currently open to the worst kinds of exploitation. We have heard nothing but silence from the government, with underfunded councils reporting that they are not receiving the help they need from Whitehall.

Meanwhile, it remains government policy to send refugees to Turkey – whose increasingly authoritarian government has just suspended human rights protection.

As if all of this were not grim enough, we have a new Secretary of State for International Development, Priti Patel, who has said that she thinks aid should be used largely to promote trade. As someone who wants our country to be respected around the world, I find this plain embarrassing. Actually, it’s worse. It’s shaming. As with Europe, so with the world: the ­Conservative government is hauling up the drawbridge just when we need more than ever to engage with people beyond our shores.

Tim Farron is the leader of the Liberal Democrats. To join the party, visit: libdems.org.uk/join

Tim Farron is leader of the Liberal Democrats.

This article first appeared in the 28 July 2016 issue of the New Statesman, Summer Double Issue