ONS decides to continue with inaccurate RPI calculation

Statistics agency chooses consistency over accuracy.

Against expectations and the recommendations of a number of influential economists, as well as its own consumer prices advisory committee, the ONS has decided not to change how the RPI – one of the two key indices measuring the rate of price inflation – is calculated.

The pressure to examine the index comes from the longstanding difference between the RPI and CPI measures of inflation. Except for the brief period in the midst of the recession, when both indices were recording deflation, RPI has consistently shown levels of inflation higher than CPI. Here's the chart for the last three years, for instance:

 

Some of that difference is due to the fact that the two indices measure subtly different things – RPI includes a broader measure of housing costs, for instance, and it ignores very high and low income households. But the ONS has known for a while that there is also a discrepancy caused by the different formulae used to calculate them.

The ONS began a consultation into whether and how it should eliminate this "formula effect", and has concluded that:

Use of the arithmetic formulation (known as the ‘Carli’ index formula) in the RPI is the primary source of the formula effect difference between the RPI and the CPI… This formulation does not meet current international standards.

So what's it going to do about it? Well, nothing:

The National Statistician also noted that there is significant value to users in maintaining the continuity of the existing RPI’s long time series without major change, so that it may continue to be used for long-term indexation and for index-linked gilts and bonds in accordance with user expectations.

Therefore, while the arithmetic formulation would not be chosen were ONS constructing a new price index, the National Statistician recommended that the formulae used at the elementary aggregate level in the RPI should remain unchanged.

The ONS will, however, develop a new measure of inflation, called RPIJ, which will use a different, better, mathematical formula.

The consumer prices advisory committee, a body which meets around five times a year to advise the ONS on measures of inflation, accepted that the ONS has a responsibility to make sure that there is a level of continuity in the RPI calculations which would be destroyed if there were a change to the formula. But, given the ONS also has a responsibility to compile those statistics "in line with best practice", CPAC concluded that not changing RPI would be "unsuitable".

On the other side, arguing for no change, were 332 of the 406 replies to the public consultation. The ONS said:

The large majority of responses did not address methodological issues but identified the impact that the changes implied… would have for them.

The competing requirements present a tricky path for the ONS to follow, but it does feel like it has picked the wrong option at this point. The job of the statistics agency is surely to produce accurate statistics, rather than statistics which are continually inaccurate in known ways. The fact that RPI is used to decide the value of, amongst other things, index-linked bonds is a reason for it to be correct, not for it to be artificially inflated.

As it stands, the ONS has decided to continue publishing a "measure" of inflation which has an accepted and understood upward bias of 1 per cent a year. It has done this, not because of any real statistical reasoning, but because greater accuracy would be bad for a majority of stakeholders. That seems like a bizarre abdication of its duty.

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.

Photo: Getty Images/AFP
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Is Yvette Cooper surging?

The bookmakers and Westminster are in a flurry. Is Yvette Cooper going to win after all? I'm not convinced. 

Is Yvette Cooper surging? The bookmakers have cut her odds, making her the second favourite after Jeremy Corbyn, and Westminster – and Labour more generally – is abuzz with chatter that it will be her, not Corbyn, who becomes leader on September 12. Are they right? A couple of thoughts:

I wouldn’t trust the bookmakers’ odds as far as I could throw them

When Jeremy Corbyn first entered the race his odds were at 100 to 1. When he secured the endorsement of Unite, Britain’s trade union, his odds were tied with Liz Kendall, who nobody – not even her closest allies – now believes will win the Labour leadership. When I first tipped the Islington North MP for the top job, his odds were still at 3 to 1.

Remember bookmakers aren’t trying to predict the future, they’re trying to turn a profit. (As are experienced betters – when Cooper’s odds were long, it was good sense to chuck some money on there, just to secure a win-win scenario. I wouldn’t be surprised if Burnham’s odds improve a bit as some people hedge for a surprise win for the shadow health secretary, too.)

I still don’t think that there is a plausible path to victory for Yvette Cooper

There is a lively debate playing out – much of it in on The Staggers – about which one of Cooper or Burnham is best-placed to stop Corbyn. Team Cooper say that their data shows that their candidate is the one to stop Corbyn. Team Burnham, unsurprisingly, say the reverse. But Team Kendall, the mayoral campaigns, and the Corbyn team also believe that it is Burnham, not Cooper, who can stop Corbyn.

They think that the shadow health secretary is a “bad bank”: full of second preferences for Corbyn. One senior Blairite, who loathes Burnham with a passion, told me that “only Andy can stop Corbyn, it’s as simple as that”.

I haven’t seen a complete breakdown of every CLP nomination – but I have seen around 40, and they support that argument. Luke Akehurst, a cheerleader for Cooper, published figures that support the “bad bank” theory as well.   Both YouGov polls show a larger pool of Corbyn second preferences among Burnham’s votes than Cooper’s.

But it doesn’t matter, because Andy Burnham can’t make the final round anyway

The “bad bank” row, while souring relations between Burnhamettes and Cooperinos even further, is interesting but academic.  Either Jeremy Corbyn will win outright or he will face Cooper in the final round. If Liz Kendall is eliminated, her second preferences will go to Cooper by an overwhelming margin.

Yes, large numbers of Kendall-supporting MPs are throwing their weight behind Burnham. But Kendall’s supporters are overwhelmingly giving their second preferences to Cooper regardless. My estimate, from both looking at CLP nominations and speaking to party members, is that around 80 to 90 per cent of Kendall’s second preferences will go to Cooper. Burnham’s gaffes – his “when it’s time” remark about Labour having a woman leader, that he appears to have a clapometer instead of a moral compass – have discredited him in him the eyes of many. While Burnham has shrunk, Cooper has grown. And for others, who can’t distinguish between Burnham and Cooper, they’d prefer to have “a crap woman rather than another crap man” in the words of one.

This holds even for Kendall backers who believe that Burnham is a bad bank. A repeated refrain from her supporters is that they simply couldn’t bring themselves to give Burnham their 2nd preference over Cooper. One senior insider, who has been telling his friends that they have to opt for Burnham over Cooper, told me that “faced with my own paper, I can’t vote for that man”.

Interventions from past leaders fall on deaf ears

A lot has happened to change the Labour party in recent years, but one often neglected aspect is this: the Labour right has lost two elections on the bounce. Yes, Ed Miliband may have rejected most of New Labour’s legacy and approach, but he was still a protégé of Gordon Brown and included figures like Rachel Reeves, Ed Balls and Jim Murphy in his shadow cabinet.  Yvette Cooper and Andy Burnham were senior figures during both defeats. And the same MPs who are now warning that Corbyn will doom the Labour Party to defeat were, just months ago, saying that Miliband was destined for Downing Street and only five years ago were saying that Gordon Brown was going to stay there.

Labour members don’t trust the press

A sizeable number of Labour party activists believe that the media is against them and will always have it in for them. They are not listening to articles about Jeremy Corbyn’s past associations or reading analyses of why Labour lost. Those big, gamechanging moments in the last month? Didn’t change anything.

100,000 people didn’t join the Labour party on deadline day to vote against Jeremy Corbyn

On the last day of registration, so many people tried to register to vote in the Labour leadership election that they broke the website. They weren’t doing so on the off-chance that the day after, Yvette Cooper would deliver the speech of her life. Yes, some of those sign-ups were duplicates, and 3,000 of them have been “purged”.  That still leaves an overwhelmingly large number of sign-ups who are going to go for Corbyn.

It doesn’t look as if anyone is turning off Corbyn

Yes, Sky News’ self-selecting poll is not representative of anything other than enthusiasm. But, equally, if Yvette Cooper is really going to beat Jeremy Corbyn, surely, surely, she wouldn’t be in third place behind Liz Kendall according to Sky’s post-debate poll. Surely she wouldn’t have been the winner according to just 6.1 per cent of viewers against Corbyn’s 80.7 per cent. 

Stephen Bush is editor of the Staggers, the New Statesman’s political blog.