Apr
27
2012

Revisions to UK GDP data

The BBC published an article entitled “Viewpoint: Is UK GDP data fit for purpose?” which featured a graph showing the original estimates for quarterly UK GDP growth and current estimates for those same figures. The point being that the original figures are subject to revision which can change figures quite significantly, for example currently we are technically in recession with a GDP growth figure for Q1 2012 of –0.2% (source). But how does this compare with the size of the revisions made to the data?

Here is the graph from the original article:

464

This is quite nice but there are other ways to display this data, which unfortunately isn’t linked directly to the graph. However, this should not stop an enterprising number-cruncher, there exists software which will allow you to extract the numbers from graphs! I used Engauge Digitizer, which worked fine for me – I had the data I wanted 20 minutes or so after I’d downloaded the software. It does some semi-automatic extraction which makes separating the two different sets of data in the graph on the basis of the colour of the lines quite easy.

This type of approach is not ideal, the sampling interval for the extracted data is not uniform, and not the same for the two datasets, furthermore the labelling of the x-axis is unclear so it’s difficult to tell exactly which quarter is referred to.

I next loaded up the data into Excel for a bit of quick and easy plotting. To address the sampling problem I used the vlookup function to give me data for each series on a quarterly basis. I can then plot interesting things like the difference between the current and original estimates for each quarter, as shown below:

DifferenceGraph

A few spot checks referring back to the original chart can convince us that we have scraped the original data moderately well. The data also fit with the ONS comment on the article:

…looking back over the last 20 quarters, between the first and most recent estimates, the absolute revision (that is, ignoring the +/- sign) is still only 0.4 percentage points.

I calculated this revision average and got roughly the same result.We can also plot the size of revisions made as a function of the current estimate of the GDP growth figure:

DifferenceGraph2

This suggests that as the current estimate of growth goes up so does the size of the revision: rises are under-estimated, falls in growth are under-estimated in the first instance although this is not a statistically strong relationship. These quarterly figures on GDP growth seem awfully noisy, which perhaps explains some of the wacky explanations for them (snow, weddings, hot weather etc etc) – they’re wild stabs at trying to explain dodgy data which doesn’t actually have an explanation.

The thing is that the “only 0.4 percentage points” that the ONS cites makes all the difference between being in recession and not being in recession!

Footnotes

I uploaded my spreadsheet here, the figures did not import well.

Apr
08
2012

Bad polling

Bullied teachers fear culture of ‘macho managers’. Union survey shows 67% were affected by abuse and harassment from their colleagues

The Observer 08.04.12

This is the headline and subtitle to an article in The Observer today. Sound terrible doesn’t it? If I were working in an organisation where 67% of the staff were being bullied I’d probably want to leave, and I’d certainly expect senior management to be addressing the problem. Fortunately I suspect this headline is almost entirely misleading.

Firstly, the first line of the article says “more than two-thirds of teachers have experienced or witnessed workplace bullying in the past 12 months” (my emphasis) – so one teacher shouting at a colleague in a busy staffroom would generate an awful lot of “yes” votes.

Secondly, it’s described as an “online poll”, giving no information on the nature of the poll. If the respondents are randomly selected then fine, however if they are self-selected then it’s close to meaningless.

It’s possible that the level of bullying of teachers by their colleagues is at the level implied by the headline, but they’ve been done a great dis-service by their union and The Observer in the poor example of polling and reporting.

You’d have thought The Observer would have learnt its lesson by now, having published a mea culpaWhen is a poll not a poll?” over a headline claiming “Nine out of 10 members of Royal College of Physicians oppose NHS bill” which highlighted exactly the issue with self-selecting surveys.

Jan
18
2012

Strike 2!

PatI’m on strike again today, as I was at the beginning of December when I took the opportunity to write quite generally about the role of trade unions (here).

This time I thought I would write a bit more specifically about why I am on strike.

I joined Unilever in 2004, at the same time joining the final salary pension scheme – I have a leaflet in front of me now explaining the “excellent benefits”. In 2007 the company announced it was closing the final salary scheme to new employees but it said that existing members could remain in the scheme, paying higher contributions to retain their benefits, this is what I have been doing since April 2008, when the changes took effect.

In April 2011 the company announced that it was intending to close the final salary scheme to current members, announcing the start of a statutory “consultation” process.

I’m one of those at the softer end of the impacts: I stand to lose 13% of my pension, prior to the consultation I stood to lose 20%. This is because my already accrued benefits will be eroded by a cap as well as the new career average scheme being less generous than the current scheme, my longer serving colleagues (of which there are many), stand to lose more.

To use an analogy: if you offer to cut my leg off but on consultation decide to only do so below the knee then you’ll find I’m not particularly impressed and explaining that you had “improved” your offer is frankly insulting.

It turns out there are specialist “Pensions Communications” companies, Unilever is using Andrew Hodges Consulting. I’m not sure if it was their idea for Unilever to use jolly little cartoons in the post-consultation communications – but it has been the most effective recruiting sergeant for the strike action!

Much has been made by Unilever of the unions “walking out” of the negotiations – this is a rather partial presentation: the unions left because the company refused to discuss any means by which the final salary scheme could be retained and would not discuss the pre-existing career average scheme in isolation with the unions.

It isn’t as if Unilever is doing badly in terms of profits and executive pay, and even the pension fund is in a pretty healthy state: as of March 2011 the scheme was 91% funded, rising from 89% in March 2010 and 69% in March 2009 – it was effected by the recession but was recovering well. With the career average scheme already in place for new employees, the liabilities of the scheme would have been reduced over the coming years. Contrary to the impression companies might give life expectancy is not improving in great leaps and bounds, it is steadily increasing in a predictable manner and has been for many years.

The company has made much of a “no-fly zone”, an offer to make no further changes for a period of a 2 or 3 years. I don’t expect to draw my pension for another 25 years or so – therefore I can anticipate a good few more changes before I retire. My view is that the company intends to have us on a defined contributions before too long. It highlights the problem with pension schemes in the private sector: how many companies can look forward for the 60 years that a pension requires?

Until recently I was proud to be an employee of Unilever, a company that led the way in looking after its workforce as well as its consumers; a company whose vision for the future was to double the size of the business without increasing the size of its environmental impact.

Today I am no longer proud to work for Unilever.

Jan
16
2012

“Nick Clegg plans more employee ownership”

In the news today: “Nick Clegg plans more employee ownership”, based on a speech to an audience in the City, citing John Lewis as a model of employee participation. John Lewis goes beyond simple employee share ownership, I own shares in Unilever – sadly this hasn’t enabled me to prevent them from cutting my pension. Channel 4’s Fact Check blog has confirmed that employee-ownership often makes for better companies.

Labour’s Shadow Business Secretary, Chuka Umunna response was:

…Mr Clegg was following Labour’s lead on responsible capitalism…

he should really check out the 2010 Liberal Democrat General Election Manifesto 2010, on p27 it says:

We believe that mutuals, co-operatives and social enterprises have an important role to play in the creation of a more balanced and mixed economy. Mutuals give people a proper stake in the places they work, spreading wealth through society, and bringing innovative and imaginative business ideas to bear on meeting local needs.

(source)

I’d argue that Labour was following the Liberal Democrats on this.

Chuka Umunna is also the chap, who said on twitter of Ed Miliband’s Radio 4 interview:

Very strong, assured performance from @Ed_Miliband on@BBCr4today this a.m

Funnily enough, Peter Hain said exactly the same thing:

V strong and assured performance by @Ed_Miliband against Humphreys @BBCr4today

Not strong evidence for original thinking.

Footnote

Screenshot here, if you don’t believe me.

Jan
12
2012

Freedom!

Scottish independence is in the air again; the Scottish National Party (SNP) won an overall majority in the Scottish Parliamentary elections in May 2011, independence for Scotland is the SNP’s signature policy and they have been pushed to state their intentions by the UK parliament (source). Independence is a natural successor to devolution which was achieved by Scotland in 1999 (source). Devolution transferred some powers from the UK parliament to the newly formed Scottish Parliament.

There is at least one anomaly in the current system: the “West Lothian Question”, originally put by Tam Dalyell, member of parliament for West Lothian in 1977:

For how long will English constituencies and English Honourable members tolerate … at least 119 Honourable Members from Scotland, Wales and Northern Ireland exercising an important, and probably often decisive, effect on English politics while they themselves have no say in the same matters in Scotland, Wales and Northern Ireland?

The label was coined by Enoch Powell.

This is not a hypothetical question: in January 2004 the then Labour government won the vote on university top-up fees by dint of the votes of Scottish Labour MPs whose constituents were unaffected by the changes since university fees are a devolved matter (source).

The West Lothian Question has not been addressed in part because for the instigators of devolution in modern times it is troublesome since it presents the possibility of a government that has a majority in the UK as a whole but not in England and Wales. The logical solution is equivalent devolution for the English regions or indeed all of England; the English regions have never shown much interest in this idea – England has not been given the choice.

From a Conservative point of view, Scottish independence now would have very welcome electoral benefits; at the last General Election, in 2010, Scotland returned 41 Labour MPs, 11 Liberal Democrat, 6 SNP, and 1 Tory MP (source). It did this on vote shares of 42%, 18.9%, 19.9% and 16.7%. The proportional result is 25 Labour, 12 Lib Dem, 12 SNP and 10 Tory. The oft-repeated quip that there are more pandas in Scotland than Tory MPs is another quirk of the first past the post system. Despite this there is unanimity amongst the national Westminster parties against Scottish independence, presumably they are all reluctant to give up territory, and the glory that Andy Murray brings.

Personally, Scottish independence would make no difference to me; experience with the European Union has shown how freely people can move for work and leisure within the Union, the likelihood is that ties between England and Scotland would be stronger than those with other EU countries. It seems such opinions are not uncommon, YouGov carried out polling after the May 2011 elections which showed 41% of respondents in England and Wales in favour of independence with only 29% of Scots in favour (source). Which begs the question: “Why aren’t our elected representatives representing our views?”

Alex Salmond finds himself in an interesting position, given current opinion poll ratings he would lose an independence poll, and if he won – where would he be? Unrequited desires for independence are the best sort.

Scotland should be entirely viable as an independent country, it has a population of around 5 million, the UK currently has a population of around 60 million. Looking at the populations of other European nations: an independent Scotland is comparable in size to Denmark, Finland and Norway and a little larger than Ireland.(source). Scotland appears to have a fairly diverse economy, financially it would seem that financial flows between Scotland and the rest of the UK are close to balance (source).

I believe in localism: that power should be devolved to the lowest practicable level. Scotland clearly is viable as a country, so my logic is that is how it should be treated.

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