Lies, damned lies and statistics

[Tizer]

The original topic `Lies, damned lies and statistics' is now in the OGFB archive and when I can get a web link for it I will add it to this post. I thought it was worth starting the topic again on the new OGFB forum because it covers so many of the day to day problems of numbers and statistics being misused by the news media, politicians, companies etc. It also overlaps with Stanley's `Department of Cunning Wheezes'. But not everything is about misuse of numbers, there is also a problem with low numeracy in our population and this is especially dangerous at a time when there is increasing need in everyday life to understand percentages, proportions, simple statistics and the meaning of numbers. I've always been a dunce at maths so don't take me for an expert trying to lecture you, all I want to do is point out some of the tricks deliberately used to baffle us, and where possible help folk to take a greater interest in numbers and not be frightened by them.

One of the first things to say here about numbers is that it's not only the rich who can make money work for them. You often hear it said that "It's alright for them, they've already got a lot of money and make more from it". But anybody who can save a few pounds regularly in a bank account that offers interest will, as if by magic, end up with more money than they've put in. This is due to the effect of compound interest. You make some interest on your initial deposit in the first year and leave it in the bank account. In the second year you make interest on the initial deposit and on the first year's interest, and so on year by year. It's claimed that Einstein said "Compound interest is the greatest discovery in mathematics"! You can use a calculator on this web page to work out the compound interest on money placed in an account: LINK

That's a good use of numbers, but there are bad uses too, and sometimes it's just down to careful use of words to avoid stating the truth. Take the latest press release from Tesco which is being bandied about by the media: "Tesco to create 20,000 new jobs". Great! 20,000 more people can get a job by working at Tesco. Well, no, it's not quite as simple as that. You have to read between the lines. Note that it doesn't say "Tesco to take on 20,000 new employees". Creating `new jobs' isn't the same thing as `taking on new employees'. You `can create new jobs' just by shuffling around your present employees or by giving them different job titles, or by doing both. Since the news media tackled the company, Tesco has thrown in comments about it being `net new job creation' but this is still beating about the bush. They are not saying that 20,000 more people will be employed by Tesco than they employ today. Nothing is ever what it seems, especially in the 21st Century!

[Whyperion]

Its over 2 years and a plan , so might not achieve. But they say these are full time permanent , based on new store openings planned and additional staff in store to improve customer service ( maybe they are going to set up more stands selling insurance/ loans , etc in store ). So its 10,000 a year and with 1000 stores it works out at 10 persons per store , say with two / three shifts early middle late its about 3 to 4 jobs per store per year extra. Not particulary difficult to plan or achieve. Each job would have to increase sales by around £200 per day to make it viable for Tesco.

[catgate]

It is all smoke and mirrors.
I went into B&Q this morning for some plumbing necessities. They had just one checkout girl operating (with a queue of five waiting as I got to it), but they had two girls "assisting the customers" at the four self checkout machines. It is obvious that all the big stores are taking up this new gimmick of self checkout.
I suppose the next thing will be self shelf stacking, or even taking a leaf out of Barmy Mick's book and just stacking the packing/transit boxes in the store so that the customer can do it all for himself.

What happened to Barmy Mick's? I remember going to B'lick two or three times when he was the only "supermarket" in Airedale. Was it late fifties or early sixties?

[PanBiker]

just stacking the packing/transit boxes in the store so that the customer can do it all for himself.

What happened to Barmy Mick's? I remember going to B'lick two or three times when he was the only "supermarket" in Airedale. Was it late fifties or early sixties?

Packing and transit boxes is the model employed by Aldi. All employees also do every job, mainly tasked by getting product out into the store. Checkout is operated on the basis of one on checkout until que reaches start of conveyor then another lane opened as required. Cash or debit card transactions only as well.

Barmy Mick was open in the late 50's and into the early sixties so your memory is OK there Catty. Site member Gus used to work for him when he was in the Palace.

[catgate]

Packing and transit boxes is the model employed by Aldi.

I think you have got Aldi mixed up with Netto.
As you say they run on a very low staff/customer ratio but they do run quite a lot of shelf stacking compared to poor old Netto R.I.P.
Lidl is also on the same system, and in my opinion they both take a lot of beating, both for price and quality. Granted one has to be careful with soft fruit, but then that is just the same throughout the supermarket world.

[Whyperion]

I quite like the self serve checkouts , but they tend to claim they dont know the weight of items ,cannot understand some bar codes / discounts want age proof for the medications , and cannot tell different apples apart. Netto have had long queues - the one at Meanwood, Leeds used to annoy me , but was cheaper than the then co-op so one put up with it.

[Stanley]

Well done Tiz! I know I am a bore but read Charlie Webster's 'Hungry or Healthy Thirties', it's in rare texts. Nothing new under the sun.
I refuse to use self-service check-outs on the grounds that I prefer dealing with human beings who are paid for their work. Catty is right, the ideal supermarket model has customers unloading the wagons at the back door. I always remember a bloke called Trevor Grice, CEO of Renolds who told me that he would buy any machine that did away with workers. Nice Man....
Just been listening to a World Service programme on the after effects of Fukushima and one of the main complaints from both the public and the scientists is that statistics are used by politicians selectively and only where they 'prove' the point.
The thing that strikes me about Tesco 'new jobs' is that they are not all full time and nobody addresses the root question as to whether they provide a living wage. Statements like 'the present CEO started as a shelf-stacker' are not evidence nor are they helpful.
Statistically speaking, a person stood with one foot in boiling water and the other on a block of ice is just fine thank you.

[Whyperion]

the machine normally needs someone to maintain and service it, of course if the machine produces so much stuff you end up with no one to buy as they have no income from making the stuff (unless they can get alternate income - from work or from state benefits levied on the profits of the producer. Its the reason I think why capitalism has financial failure built in to the concept ( there is seeming success as long as the pyramid is big enough until it all falls down ).

[Bodger]

I worked in the injection moulding industry, one ad i recall for a German made machine advertised their machines would run 24 hours with only one man and a dog, the dog to stop the man from adjusting the micro processor controlled machine settings, and the man to feed the dog.

[Bruff]

I will no more use self-service checkouts than go and 'pick my own' from a fruit farm. I am not in the business of providing my labour free to commercial enterprises.

Ben Goldacre's book 'Bad Science' is indispensible as a guide to the misuse of statistics (and evidence more generally), particularly the difficulty in dealing with small numbers/rare events. His demolition of the outcry that usually accompanies the latest release of a criminal who reoffends after being judged safe by the experts, should be required reading by anyone.

Anyway, what's the average number of legs on a human being?

Richard Broughton

[Whyperion]

Self Serve checkouts good , they take the non uk current coins that I seem to get given in change by real people in shops and post offices.

I can pack at my own speed without a conveyor running at the checkout staffs deemed rate of too fast. too slow, easy reuse my bags.

About 1 and 15/16ths at a guess. (Sorry 90% have Two , 5% 1 , and the rest somewhere less than 1 , or between 1 and 2 ) - you need one of those bar charts we did at school for that without the lines joining them.

[Stanley]

Check out machines don't commiserate with you when you have a cold. Marx made the point about dilution of skills and redundancy of labour in Das Kapital.
Richard, right on! Love the stat about number of legs.... Can't remember the source but there used to be an almost exact correlation in Ireland between the number of barrels of Guinness produced and RC ordinations annually.
I've written too many grant applications to have any confidence in economic benefit projections based on statistics. Yes, I was one of the Guilty Men! Talk about creative writing......

[Whyperion]

With the news of 6 Army personnel killed in Afganistan and the comment that they had only been on service there for 3 weeks , as if there is a statistical probability of length of time and getting a hit from a roadside device. Actually there probably is , you could make arguments that a longer time gives you more information to gather to avoid such events , balanced with fatigue for staying out too long with readyness and training for new deployments. Device has been reported as possibly a Soviet land mine from previous occupants' time in Afganistan, otherwise it seems a rather large explosive to take out an alleged better armoured vehicle.

[Stanley]

I'm afraid that like a lot of other people I have gone numb over Afghanistan. We should never have been in there and the deaths at present are solely due to the 'leaders' trying to massage their exit strategy. All the evidence is that the area falls to pieces as soon as troops come out and then they will have to try to explain what difference we made. They are almost certain now that it was an old Soviet mine containing 60kg of explosives. Though weighing 25 tons, the armoured vehicle didn't have the 'V' shaped base that resists explosions better.
I see the Telegraph is saying we should stay there until the threat of it becoming a terrorist state is assured. What a load of crap. Haven't they noticed anything that has been happening? Anyone who still believes the lie about 'The War on Terror' should be certified and put somewhere where they can do no harm.

[Tizer]

There's a letter in Saga Magazine pointing out that the Office for National Statistics mis-uses statistics when it claims that older couple are becoming more likely to divorce than young couples. The letter says how older couples are more likely to be married whereas many young couples are unmarried, so the ONS claim might be technically correct but it fails to give a real impression of the numbers of long-term relationships breaking up. If young couples don't marry, they can't divorce and therefore don't show up in the stats even though their relationship fails.

[catgate]

There's a letter in Saga Magazine pointing out that the Office for National Statistics mis-uses statistics when it claims that older couple are becoming more likely to divorce than young couples. The letter says how older couples are more likely to be married whereas many young couples are unmarried, so the ONS claim might be technically correct but it fails to give a real impression of the numbers of long-term relationships breaking up. If young couples don't marry, they can't divorce and therefore don't show up in the stats even thought there relations hip fails.

Do they perhaps look upong same sex couples as a Standard Deviation????

[Stanley]

Tiz, a good example of how a partial statistic can be misleading.

[Stanley]

An 'expert' advocating mining of asteroids this morning on World Service: "Each asteroid contains 20,000 tons of aluminium, platinum and gold worth 20,000 billion dollars". Sounds convincing until you start to ask questions like "How does he know this?"

[Whyperion]

Spectroscopy Analysis ?
But I thought most asteroids were about the size of a football ?

[PanBiker]

Spectroscopy Analysis ?
But I thought most asteroids were about the size of a football ?

Are you confusing asteroids with meteorites? Many started off as asteroids but ended up as the small chunks that enter our atmosphere and generally burn up. Any surviving remains of meteorites are very valuable and some people make a living by searching and retrieving them then selling them on for research.

I'm fairly sure asteroids come in all sizes including the big ones that Earth scientists monitor for as potential "planet killers". There are some very big rocks out there.

[Stanley]

Apart from anything else there is another flaw in the reasoning. Suppose it did work and massive amounts of rare metals were brought to planet Earth, what effect would increased supply have on commodity price? De Beers have the same problem and regulate the supply to the market to keep gem prices up.

[Tizer]

One of the first questions any miner or processor would ask is: "What is the concentration of the desirable minerals?" It's not good enough for them to say there are 20,000 tones of X - if it's at a very low concentration it won't be worth mining. There are vast amounts of aluminium, platinum and gold under our feet but most of it is at too low a concentration to be economic. As for how do they know it's there, as Whippy says they use spectroscopy. But the trouble is that this detects elements (like aluminium, platinum and gold) and doesn't tell you how easy or difficult it will be to extract them. Also I don't know how quantitative the method is for astronomical purposes and the 20,000 tons may just be an estimate of the size of the asteroid and an assumption that it's completely made up of aluminium, platinum and gold!

[Bodger]

Rather than going into space, start at home extracting from suspension the gold and other valuable commodities from the oceans, it would cut down on transportation costs

[Stanley]

Dead right Bodge but the problem is the one identified by Tiz, the concentration is so low.
Interesting to hear the statisticians commenting on the accuracy of the -2% growth figure. Despite the fact that according to them only 40% of the data is in and even that is of doubtful accuracy, the publication of the figure governs how the markets and rating agencies react. It's the old problem, economists can only react to what has happened and their opinions are affected by the accuracy or otherwise of the figures. My suspicion at the moment is that the retail figures on the High Street are suspiciously high. How are they managing to buck the trend against the reality of falling personal disposable incomes? Further, is it at the expense of profits and could this be the elephant in the room? Same applies to the employment figures, how many of the jobs are viable, do they pay a living wage?

[Whyperion]

Panbiker , in terms of number of Asteroids in the normal location ( after Mars ) , most are dust to not much bigger , then there are more sizes but fewer of them , relatively. If they are from a broken up planet then any minerals should be easy to find as all near the surface of the object.

Economic Activity , are any of these stats looked at in terms of things like total resident population , total working population. There are more people in work ( at slightly lower average wages ) , which is allowing retail sales to bear up rather well , ( and there has been a big increase in inflation so volumes I would guess are down , but values up ). Construction - cannot really think of a cause but was not this time last year Westfield and Olympic area in London in full flow , but last three months have been back end of the work so little in value billed. ( not that London is the whole driver for the UK but I am struggling to think of major projects elsewhere ).