Hackney statistics - don't try this at home

Last week Blood and Property published this story: Hackney's 1600 'ghost' workers and 28 'ghost' claimants

The Office of National Statistics and Hackney Council both supplied explanations for why these figures were not useful.

The statement from the ONS says that the reasons for the discrepancies are 'horribly teccy' so I may have misunderstood them. But from what I did understand, the discrepancy of 28 'ghost' claimants was explained, but I'm still not clear on the 2% leap in the size of the Hackney North working population.

So, what did Hackney Council say?

In response to the claim that there were 28 'ghost' Job Seekers Allowance claimants in Hackney following boundary changes, Hackney Council sent these clipped comments:

Sentence 1: "Data showing total number of claimants for Hackney borough boundaries based on 1991 ward boundaries, however parliamentary constituency data based on recent 2010 revisions."

Sentence 2: "Hence difference in claimant numbers for Hackney vs Hackney constituencies."

Sentence 3: "Hoped that ONS will update JSA claimant numbers (for Hackney) from 1991 boundaries soon."

What I think this means: The ONS separates its data into different categories:

JSA claimants per parliamentary constituency
JSA claimants per local authority

And when the ONS calculates the number of JSA claimants for the whole of Hackney it does so by looking at the borough's 1991 ward boundaries.

However, when the ONS calculates the number of JSA claimants for Hackney's two parliamentary constituencies, Hackney North and Hackney South, it calculates the number of claimants using the latest 2010 revisions.

Before the 2010 constituency changes, figures for Hackney North and Hackney South added up to equal the borough total. But they didn't in March this year. There were 28 fewer claimants across the borough when adding Hackney North and Hackney South than there were from the ONS borough-wide figure.

The latest figures show a discrepancy of 20 claimants between the combined total of Hackney North and South and the ONS local authority total. So it is not a one-off glitch. The new constituency figures show a rosier view - fewer JSA claimants.

So the explanation for the discrepancy is this difference between using 1991 and 2010 areas - this is explained in greater detail by the ONS below.

Then Hackney Council took a look at the claim that 1600 ghost workers appeared in Hackney North after the boundary changes:

Sentence 1 (I think this is just the Council describing what I did): "Based on extrapolated working age population combined with averaging monthly data."

Sentence 2 (What the council thought of extrapolation): "Caution against this: constituency rates use mid-2007 population estimates as denominators, whereas borough rates use mid-2008 population estimates as denominators - data on population size and economic activity based on surveys and estimates, always have certain error term."

Sentence 3: "ONS population estimates in Hackney likely underestimating population compared to administrative data (eg via GP surgeries) and GLA population estimates."

I think this is saying that my attempt to compare the population sizes pre and post constituency boundary change, is dodgy. Which is probably true but I don't think that this bit of the council response explains why. Here the council 'caution' against comparing borough data with constituency data. But I didn't use borough-wide data to come up with the 1630 ghost worker figure, just constituency data.

I used the number of JSA claimants in Hackney North - which in January 2010 was 4,402 supplied by ONS. The ONS also say what percentage of the working population this is. In this case, Jan 2010, it was 6.3%. So, using these figures, the Hackney North working population was 69,873 - (4,402/0.063=69,873).
and, in..
February 2010 - 4,450 (6.4%) - (4,450/0.064=69,531)
March 2010 - 4,336 (6.2%) - (4,336/0.062=69,935)
April 2010 - 4,727 (6.3%) - (4,727/0.063=75,031)
May 2010 - 4,637 (6.2%) - (4,637/0.062=74,790)


For Hackney South:
January - 5503 (7.6%) - (5503/0.076)=72,407)
February - 5,594 (7.7%) - (5,594/0.077=72,649)
March - 5,510 (7.6%) - (5,510/0.076=72,500)
April - 4,908 (7.1%) - (4908/0.071=69,126)
May - 4,959 (7.2%) - (4,959/0.072=68,875)

The discrepancy appeared between February and March 2010 when the working population in Hackney North increased by about 5000 people. Meanwhile the Hackney South working population shrunk by about 3300. It seemed fair to assume that, because these changes were caused by constituency boundary changes, that any increase in the north should have been mirrored by a decrease in the south.

But the figures show that while Hackney North's working population increased by 5000, about 7%, 1600 of these did not come from Hackney South. An unexplained 2%. I'm not sure the council has answered this question (but I'm not sure!).

Then there's the ONS answer. This seems to confirm the Council's explanation about the 28 'ghost' JSA claimants. But I couldn't quite identify the explanation for the 1600 mystery increase in Hackney North's working population - but that doesn't mean it wasn't there. I suspect it is in the bold sentence at the end. But the bold sentence at the end is only for bold people.

ONS: "I am afraid there are some horrible teccy reasons, regarding the way in which figures for geographic areas are created, how systems change over time, when published population estimates get incorporated into statistical sources etc that are behind these discrepancies - but I will try to explain some of it.

"Firstly, the JSA figures. The older system used for aggregating JSA data to higher levels did so by aggregating to a layer of ward geography that was frozen at a point in time - and then aggregating from these wards to higher geography levels. This is the way in which the local authority JSA counts are created and the way in which the old parliamentary constituencies are created. So for JSA, LA and old PC were consistent.

"However, this method is not considered to be 'best practice' for currently produced aggregation - this is because ward boundaries change, so the frozen wards are out of date and no longer align with a real geography and a few other technical issues. The current best practice is to aggregate to a static statistical building block, known as output areas, which were designed using data relating to the last census. There are around 34,000 of the Lower Layer Super Output Areas (LSOA) - they don't necessarily exactly align with existing geography boundaries - but they are static, of similar size and provide a 'consistent' building block for statistical purposes. They also don't change, get re-used, get used on a temporary basis etc like a geography such as postcodes does. The idea is that if all statistics for all geographies are built from these building blocks, then they may not be precisely accurate with all those geography boundaries - but if everyone does it in the same way, they will be inaccurate in consistent ways and give comparable statistics. The problem is that people are only moving to this best practice as and when new system and requirements are built, simply because of the inefficiency of rewriting all the numerous existing systems in place.

"So - for JSA, LA and old PC are both created from aggregating frozen ward based information. For the 2010 Parliamentary Constituencies they are built on the new basis from LSOAs. So the LA and PC2010 are built on a slightly different geographic building block basis.

"The other figures that you quote will have similar although slightly different issues involved............including population estimate calculation being optimised to calculate LA level figures, which are later modelled to LSOAs, which are then used to construct PCs; employment estimates being based on a combination of direct postcode to LA lookups and PCs constructed from LSOAs; and an added complicaton that survey estimates only reweight to population estimates once a year, so the latest survey estimates are currently based on last year's published population estimates rather than the most recently published."

A character building sentence!

Hackney's 1600 'ghost' workers and 28 'ghost' claimants

When constituency boundary changes came into effect in April 2010 - before the General Election - the number of Job Seekers Allowance claimants rose by 391 in Hackney North. In Hackney South the number of JSA claimants fell by 602.

Together this meant that the number of people claiming Job Seeker's Allowance should have fallen by 211 across the borough as a whole.

+ 391
- 602
= - 211

But according to the Office of National Statistics figures, the net fall in JSA claimants in Hackney, over that period, was 183. (Figures from documents listed on this ONS web page)

This 183 figure matches the ONS's breakdown of male/female JSA claimant figures in the borough but not its Hackney North/Hackney South total. I don't know if this kind of discrepancy is normal - it didn't happen in the month prior to the boundary changes.

The change in constituency boundaries also seemed to generate an estimated 1630 new working-age people in Hackney North. This wouldn't have been surprising if they had previously existed in Hackney South. But the figures suggest that they didn't.

The boundary changes saw the Hackney South working population fall from 72,500 (average of three figures) to 69,000 (average of the two figures). So, across Hackney South, there appears to have been a decrease in working population of about 3500 (72,500-69,000=3500)

Meanwhile, the Hackney North population rose from 69,780 (average of three figures) to 74,910 (average of two figures) - meaning that the Hackney North population increased by 5130 (74910-69,780=5130)

So, the boundary change seems to have resulted in about 1630 previously non-existent workers appearing in the borough (5130-3500=1630) all of them in Hackney North.

The Boundary Commission changes (details below) were made because the number of voters in Hackney constituencies were considered too low to justify having two MPs.

Latest Hackney JSA claimant count:

2010: working population extrapolated from figures in red.
May: 9,616 (6.7%) (9,616/.067=143,522)- next is Tower Hamlets with 6.6%
April: 9,663 (6.7%) (9,663/.067=144,223) - next is Tower Hamlets with 6.5%
March: 9,846 (6.8%) (9,846/0.68=144,794) - next is Tower Hamlets with 6.6%
February: 10,044 (7%) - next highest is Tower Hamlets with 6.7%
January: 9,905 (6.9%) - next highest is Tower Hamlets at 6.6%
2009
December: 9743 (6.7%) - next highest was Tower Hamlets at 6.5%
November: 9,795 (6.8%) - next highest was Tower Hamlets at 6.7%
October: 9,827 (6.8%) - equal highest with Tower Hamlets.
September: 9,884 (7%)
August 9,826 (6.9%)
July: 9550 (6.7%)

Divided into constituencies: - Diane Abbott (North) and Meg Hillier (South) -

Hackney North
May - 4,081
June - 4,118
July - 4206
August - 4,331
September - 4,338
October - 4365
November - 4386 (6.3%)
December - 4331 (6.2%)
January - 4,402 (6.3%) - (4,402/0.063=69,873)
February - 4,450 (6.4%) - (4,450/0.064=69,531)
March - 4,336 (6.2%) - (4,336/0.062=69,935)
April - 4,727 (6.3%) - (4,727/0.063=75,031)
May - 4,637 (6.2%) - (4,637/0.062=74,790)


Hackney South
May - 5,296
June - 5,190
July - 5,344
August - 5,495
September - 5,546 (7.8%)
October - 5,462
November - 5,409 (7.5%)
December - 5,412 (7.5%)
January - 5503 (7.6%) - (5503/0.076)=72,407)
February - 5,594 (7.7%) - (5,594/0.077=72,649)
March - 5,510 (7.6%) - (5,510/0.076=72,500)
April - 4,908 (7.1%) - (4908/0.071=69,126)
May - 4,959 (7.2%) - (4,959/0.072=68,875)


Background from Boundary Commission Report: "3.12 The constituency with the lowest 2000 electorate in London will be Hackney South and Shoreditch BC with 57,204 electors: this will be the second lowest electorate in England after that of Wirral West BC. This constituency electorate is 12,731 below the electorate quota, but only 2,991 below the Hackney borough average of 60,195. Although the borough average is within 260 electors of the 10,000 threshold, we nevertheless considered pairing Hackney with a neighbouring borough. However, we concluded that there was no suitable partner that was not already paired with another borough or one that met our criteria for pairing.

25. In relation to the second counter-proposal as it affected Hackney, the Assistant
Commissioner reported that, from the evidence gained at the inquiry and as a result of his own observations on site visits, the Dalston ward was more closely associated with Stoke Newington and the northern constituency in terms of local community and transport links, and that the King’s Park ward was more closely associated with Hackney South and Shoreditch BC. He stated that, were it simply the question of the King’s Park ward, he would have been less persuaded to recommend a departure from the provisional recommendations.However, the close association of Dalston with Stoke Newington appeared to him to be compelling. For these reasons, he recommended that the changes put forward in the second counter-proposal in relation to Hackney should be adopted and that there should be no change to our provisionally recommended constituencies in Islington.

29. We agreed with the Assistant Commissioner that there was no need to group Hackney,
Islington, and Tower Hamlets. We also agreed with his recommendation that the Hackney
Borough ward of Dalston should be included in Hackney North and Stoke Newington BC, the Hackney Borough ward of King’s Park ward should be included in Hackney South and
Shoreditch BC and the Newham Borough ward of Canning Town South should be included in
West Ham BC.

Recommendation

32. We therefore recommend the adoption of the following eight constituencies in Hackney, Islington, Newham, and Tower Hamlets containing the wards listed in Appendix C:-

2000 electorate

Hackney North and Stoke Newington BC 63,185
Hackney South and Shoreditch BC 57,204
120,389

Unemployed in Hackney - the lull before the storm

I was made redundant in June and signed on at the Jobcentre Plus on Mare Street last week. It was not an unpleasant experience.

The only disconcerting thing about it was that the unemployed seemed to be outnumbered by Jobcentre staff. There was a friendly gang to usher me in and two members of staff sitting behind every desk.

The silent observant ones, I was told, were the new recruits getting their training. There seemed to be a lot them.

As luck would have it, Derek Harvey, External Relations Manager for Jobcentre Plus across East London, was at the Overview and Scrutiny Board meeting on Thursday (16 July) and I asked him why there were so many new staff at the Jobcentre Plus.

Yes, a daft question, but I thought there was a chance that there might be a happy answer as Derek had just delivered the only real good news to the O&S board – that Hackney’s job seekers allowance (JSA) claimant count had fallen for the first time since September.

(Office of National Statistics Regional Monthly Data - July 2009 show the number of claimants has dropped across the borough from 9350 in May to 9308 in June. The biggest fall is in Hackney South and Shoreditch down from 5296 in May to 5190 in June. The figures were still on the rise in Hackney North, up from 4,081 in May to 4,118 in June. It sounded vaguely optimisic – it was presented as vaguely optimistic.)

So when Derek left the meeting I ran after him to ask if he really thought the news was good and, if so, why Jobcentre Plus had so many new faces. All he could say was that Jobcentre Plus was “gearing up to handle greater volumes” and that I should ask Jobcentre Plus’s press office for details of recruitment in Hackney.

Unfortunately the Jobcentre press office couldn’t provide those figures. Considering the borough’s claimant count fell by just 42 in June, it might have been interesting to see if Jobcentre recruitment helped keep the numbers down (although the new people might well not be from Hackney).

The national figures are pretty interesting though – apologies if everyone knows them already. In November last year Jobcentre Plus was given cash to recruit 6000 new staff and in April it was given cash to recruit another 10,000 - that’s 16,000 jobs.

So far, since the November 2008 cash injection, Jobcentre Plus has employed 9,000 new staff leaving room for another 7,000.

The press officer I spoke to said that, so far, there had been no problems with providing a decent service and that the time it was taking to process claims was within targets.

It seemed fair to ask how bad things might get. But I was told that no one at the Department of Work and Pensions was into the forecasting game – apparently it's none of their business, not even a guess was allowed. We both became a little embarrassed when I kept asking how the government had come up with this 16,000 figure for new staff.

I was too thick to see that there are other ways of doing this - it had something to do with the state of the economy, not how many people might lose their jobs.

Luckily a few economists have had a go at this forecasting lark and none of them were optimistic.

For Hackney though, the hope is that the new Jobcentre recruits will be twiddling their thumbs til I drop in again on Wednesday.

Will Hackney return to 17% unemployment?

Hackney had the biggest rises in employment – should we expect the biggest falls? Socialist candidate says yes.