Global warming and externalities

How a carbon tax can "solve" global warming

Tim Worstall (yes, when he's not trolling he's quite good) has a piece up at the Telegraph explaining how carbon taxes work, and why they could "solve" global warming:

In economic theory, the problem here is that my actions that create emissions also damage someone else. But I don't have to pay for the damage I've caused. This is called an externality and the economists' solution is something called a Pigou Tax. That is, we add a tax equal to the damage I'm doing, so that I do pay for that damage.

Worstall cites the Stern Review's figure of $80 per tonne of CO2 as a good starting ground for where to set a carbon tax, and explains why it's the most efficient way to deal with climate change:

As a made-up example: my car emits one tonne CO2 when I drive it to buy fresh bread for lunch. That's $80 of damage I cause in the future by doing so. But the benefit to me is trivial: if you paid me 50p (alright, £5 in the rain) I'd cycle instead and not emit the CO2. The value to me of driving is that 50p; the costs to someone else are the $80. Clearly, this is a bad deal for everyone else: they're bearing costs much greater than the benefit to anyone at all. An $80 a tonne tax would get me cycling and that would be a good thing: I've stopped doing something where the benefit is lower than the cost.

However, we've a pregnant woman in pre-eclampsia. She needs to go to hospital in an ambulance which is going to emit that tonne, that $80 worth of CO2. Without it she and the child will be dead; with it they'll be fine. We usually value a statistical life in the £2 – 3 million range. That's what the railways will spend on safety to save a life on average. Or we could use the £50,000 that NICE applies to one year of good-quality life. If your drug treatment costs more than this, then you won't get it on the NHS; less and you might. Different numbers but much the same outcome: burn that fuel and damn the $80 of future damages, because they're much lower than the benefits that are achieved right now from burning that fuel.

This efficiency is why a carbon tax – or the harder to impose, but fairer and economically identical "cap-and-trade" system – really is the best way to deal with global warming. By definition, it deals with "bad" emissions while allowing "good" ones, and it does so far better than a legislature could ever hope to with a sprawling network of tariffs and subsidies.

But Worstall does somewhat overstate the case in one area, when he writes:

The other part [of a reader's question] – what's the point if we're not going to spend the money on green projects? – misunderstands the purpose of the tax. We're not trying to raise money: we're trying to change prices.

Changing prices is only half the effect of a carbon tax – or any Pigou tax. The other half is compensating the "victim" for their loss.

Suppose we live in a little two person economy where every tonne of CO2 you produce causes $80 worth of flooding damage to me. Imposing a carbon tax solves half the problem, in that it stops you polluting if you only get $10 benefit from it. But it doesn't solve what happens if you can make $100 from polluting.

In that case, you pay $80, and make $20 profit. I'm still left with $80 of flooding damage. The proper use of the money raised is to compensate the me for that loss. Otherwise, a tax which merely sorts out externalities becomes a revenue-raising tool of Government. In practice, this means that money raised from a carbon tax should be used on "green projects".

Which would annoy Worstall's fellow Telegraph blogger James Delingpole.

Anti-carbon tax protestors in Australia. Photograph: Getty Images

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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Why isn't Labour putting forward Corbynite candidates?

Despite his successes as a candidate, the organisational victories have gone the way of Corbyn's opponents. 

The contest changes, but the result remains the same: Jeremy Corbyn’s preferred candidate defeated in a parliamentary selection. Afzhal Khan is Labour’s candidate in the Manchester Gorton by-election and the overwhelming favourite to be the seat’s next MP.

Although Khan, an MEP, was one of  the minority of Labour’s European MPs to dissent from a letter from the European parliamentary Labour party calling for Jeremy Corbyn to go in the summer of 2016, he backed Andy Burnham and Tom Watson in 2015, and it is widely believed, fairly or unfairly, that Khan had, as one local activist put it, “the brains to know which way the wind was blowing” rather than being a pukka Corbynite.

For the leader’s office, it was a double defeat;  their preferred candidate, Sam Wheeler, was kept off the longlist, when the party’s Corbynsceptics allied with the party’s BAME leadership to draw up an all ethnic minority shortlist, and Yasmine Dar, their back-up option, was narrowly defeated by Khan among members in Manchester Gorton.

But even when the leadership has got its preferred candidate to the contest, they have been defeated. That even happened in Copeland, where the shortlist was drawn up by Corbynites and designed to advantage Rachel Holliday, the leader’s office preferred candidate.

Why does the Labour left keep losing? Supporters combination of bad luck and bad decisions for the defeat.

In Oldham West, where Michael Meacher, a committed supporter of Jeremy Corbyn’s, was succeeded by Jim McMahon, who voted for Liz Kendall, McMahon was seen to be so far ahead that they had no credible chance of stopping him. Rosena Allin-Khan was a near-perfect candidate to hold the seat of Tooting: a doctor at the local hospital, the seat’s largest employer, with links to both the Polish and Pakistani communities that make up the seat’s biggest minority blocs.  Gillian Troughton, who won the Copeland selection, is a respected local councillor.

But the leadership has also made bad decisions, some claim.  The failure to get a candidate in Manchester Gorton was particularly egregious, as one trade unionist puts it: “We all knew that Gerald was not going to make it [until 2020], they had a local boy with good connections to the trade unions, that contest should have been theirs for the taking”. Instead, they lost control of the selection panel because Jeremy Corbyn missed an NEC meeting – the NEC is hung at present as the Corbynsceptics sacrificed their majority of one to retain the chair – and with it their best chance of taking the seat.

Others close to the leadership point out that for the first year of Corbyn’s leadership, the leader’s office was more preoccupied with the struggle for survival than it was with getting more of its people in. Decisions in by-elections were taken on the hop and often in a way that led to problems later down the line. It made sense to keep Mo Azam, from the party’s left, off the shortlist in Oldham West when Labour MPs were worried for their own seats and about the Ukip effect if Labour selected a minority candidate. But that enraged the party’s minority politicians and led directly to the all-ethnic-minority shortlist in Manchester Gorton.

They also point out that the party's councillor base, from where many candidates are drawn, is still largely Corbynsceptic, though they hope that this will change in the next round of local government selections. (Councillors must go through a reselection process at every election.)

But the biggest shift has very little to do with the Labour leadership. The big victories for the Labour left in internal battles under Ed Miliband were the result of Unite and the GMB working together. Now they are, for various reasons, at odds and the GMB has proven significantly better at working shortlists and campaigning for its members to become MPs.  That helps Corbynsceptics. “The reason why so many of the unions supported Jeremy the first time,” one senior Corbynite argues, “Is they wanted to move the Labour party a little bit to the left. They didn’t want a socialist transformation of the Labour party. And actually if you look at the people getting selected they are not Corbynites, but they are not Blairites either, and that’s what the unions wanted.”

Regardless of why, it means that, two years into Corbyn’s leadership, the Labour left finds itself smaller in parliament than it was at the beginning.  

Stephen Bush is special correspondent at the New Statesman. His daily briefing, Morning Call, provides a quick and essential guide to British politics.