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Examining the numbers behind Andy Burnham’s ‘Manchester Miracle’
00:28:29
Tim Harford examines ‘Manchesterism’, hot cities, whales and CO2, and prime numbers.
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A
Hello and welcome to More or Less. I'm Tim Harford and we are your weekly guide to the numbers all around us. From the sizzling skyscrapers of the world's great cities to the cool depths of the Pacific Ocean, from the infinite mysteries of the primes as they float in Plato's realm of forms. To Manchester. Well, it had to happen. On Monday morning, Andy Burnham, the former mayor of Greater Manchester, the new MP for Makerfield and the definitely not the Prime Minister, gave a big speech outlining his vision to transform the UK economy. This speech was given where else? In Manchester, the city where he was mayor from 2017 until a couple of weeks ago. And that has now given rise to a new addition to the economic phrasebook. This is Manchesterism. Manchesterism, Burnham told us, can, can be a model for the rest of the UK in its search for that long awaited economic growth that has proved so elusive. And to achieve long term economic growth, as any economist will tell you, you need to increase productivity, the amount of economic output you get for every hour worked. And if you look at the economic record of Greater Manchester and Andy Burnham, well, according to the official statistics, something remarkable stuck seems to have happened. Here's Paul Swinney, chief economist at the Data City.
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So if we look at the statistics from the ons, it tells a story for Manchester which is very similar to the UK up until around about 2018, 2019 time, which is that productivity has been flat, being very little change in how much people produce for the hours that they put in at work, which is really important because it has an impact on wages ultimately. And that's the thing that people care about, how much money is in their pockets.
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A
Okay, so disappointing in Manchester and in the UK until 2019 and then, and
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B
then all of a sudden there was a miracle where Manchester grows, or Greater Manchester grows from having productivity growth on average of 0.5% from 2008 to 2019 to then a growth of 3.3% per year on average from 2019 through to 2023. That's a pretty amazing performance. On the face of it.
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A
2023 is the most recent date for which we have regional figures, by the way, if you turn these annual figures into C totals, then between 2019 and 2023 productivity grew by about 14% in Greater Manchester. That's an impressive number. The UK figure for the same period is about 3%. But is it too impressive?
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B
When I first thought, when I looked at the data, it was, that can't be real. That is quite an incredible performance. If we think about the challenges that the UK has faced as a country since 2008 with its totally flatlining productivity.
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Something else prompted Paul to raise an eyebrow. If productivity was sharply increasing in Manchester, I would expect to see wages also to sharply increase. Have they?
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B
They haven't. So Productivity rises by 14% in the data, but real wages rise by around about 1%, which is a huge divergence.
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A
This presents us with a bit of a dilemma. Either productivity growth did jump up, but few of the benefits were reflected in median wages, or the jump never happened. So Paul started digging into the data, starting with the economic output part of the equation, and he found something a bit odd.
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B
And so if we look at it on a sectoral basis, we can see that legal and accounting, there was something very, very strange going on there where a very large share of the country's overall growth in legal and accounting was occurring not just in Greater Manchester, but in Trafford local authority in particular. An enormous amount of growth for one local authority.
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A
That sounds like one big firm or cluster of firms.
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B
Very, potentially, yes. But that could be real. It could be. So thought, okay, well let's can't get any further with that data, so let's try and look at a different data source and let's look at jobs where we can get more fine grained detail on jobs from a sector perspective, but also from a geography perspective too. And zooming in on that, what you then see is that this growth in legal and accounting, there was a huge spike in jobs, about 21,000 extra jobs added over this quite short period. And they were added in a very particular part of Trafford around the navigation role train station. Now if you look at this place from a map, from the air, you can see lots of houses, but you definitely can't really see somewhere that's going to be housed. Not just many thousands of jobs, but an increase of many thousands of jobs.
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A
So what's going on there?
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B
My suspicion on that would be that it's the way the data was collected. And I'd imagine there's probably been one accounting company that maybe provides services across the country that has been telling the ONS that it's got many bases across the country and then it's changed how it reports that data and it's giving the ONS data saying that all comes out of perhaps one branch or one maybe headquarters that is based in that area, rather than the true representation of where their activity is taking place.
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A
So if you did decide that you didn't trust this particular bit of data and decided to disregard it, does that remove the story of Manchester's productivity growth.
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B
It doesn't. What would happen is that productivity would go from being 14% over this period to down to 12%. So it's adjustment, it's quite a large adjustment for just changing one thing 12%.
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A
Productivity growth is still not to be sneezed at much better than the rest of the uk. But we still need to look at the other part of the productivity equation. Remember, productivity is output divided by hours worked. So should we believe the data describing hours worked?
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B
The curious thing is that despite seeing very strong output growth and despite seeing very strong jobs growth over this period, hours worked goes down. It falls by 2% over the period. Now that's not impossible to happen, but again it's pretty unlikely. So again you have to put the jigsaw pieces together on this to try and figure out what's going on. And Resolution foundation and Centre for Cities two think tanks had done some work on this that I was able to borrow and what they saw was that there was a change in the composition of the statistics where there was a large drop off the number of self employed people who were registering hours in the labor force survey, which is where the data comes from for hours worked. Now when they then cross checked that with output from the HMRC which also collects data on this type of thing from a tax perspective, the HMRC data says there wasn't a drop off in self employment. And I think what this points to is that there's been some issue with the survey around capturing self employed people in particular that for some reason that's where the fall is.
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As loyal listeners will well know, there have been big problems with the ONS's Labour Force Survey as response rates plunged during the pandemic and after at one point the M and S had to suspend publication.
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B
And I think if you then make that adjustment again as a second adjustment to this data, you can then see the growth of productivity falls again. So it is still outpacing the national average, which in itself was very, very weak. But when you've then made these two steps all of a sudden this miracle starts to go away.
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These problems with the data aren't because of anything Andy Burnham has done. These are official statistics from the ons. But. But it does feel like we need to treat the stats with a bit of skepticism. So how much? Liam Sydes is associate director of Oxford Economics and leads its citizanalysis. He thinks Paul is right to be skeptical and there are some fishy things.
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C
But I personally from the data that We've been looking at and cross comparing it with different data sources, think that the general story of outperformance does hold. And the more that I've looked into this, the more I think this view probably is true. So I think the story of Manchester outperformance still is there. I think it's the magnitude that is up for question.
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Liam points to some alternative data sources to corroborate the idea that Greater Manchester is still leading the way economically. And that's partly due to investment in the area.
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That investment has been centred around professional services and information and technology, two sectors that over the last four years have led UK productivity growth.
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Greater Manchester has also seen strong increases in the working age population. There's been a 1.2% increase in Greater Manchester between 2019 and 2023, while the national average is 0.7%.
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C
You can see the increase in knowledge intensive business jobs, you can see the increase in jobs in professional service sectors and so on. That's telling me that businesses want to be there as well because they're employing these people.
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A
So even if there hasn't been a sudden productivity miracle in the last few years, it does seem hard to deny that man has seen substantial economic improvement over the long run. Although both our experts agree that the foundations for this were put in place well before Andy Burnham became mayor in 2017. So are these policies replicable? Could Manchesterism, like Boddington's in Cairns be spread around the country? Will it lead to growth in every postcode as Andy Burnham has pledged?
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C
Liam Sides the most basic answer is yes, these can definitely work in other cities of the uk. The challenge here comes on. What about the smaller cities? And what about towns that aren't near a city? It's quite difficult to see how, I don't know, places like Middlesbrough maybe can benefit from this model of growth.
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Our thanks to Paul Swinney and Liam Sides. We asked the ONS about the doubts raised about Greater Manchester's productivity stats. They told us that they calculate regional data by balancing around range of sources to produce the best estimates possible, but that there is obviously a greater level of uncertainty at a regional level than with aggregate UK figures. You're listening to more or less. Unless you've been living under a lovely cool rock, you might have noticed some rather hot weather of late. And seeing as climate change is heating up the planet, some of you might be thinking of investing in air conditioning in preparation for the next baking event. But over on Channel 4 News, Lucilia Rodriguez, a professor of sustainable and resilient Cities at the University of Nottingham had a warning for those so tempted.
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The problem with air conditioning is it causes more problems.
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So as you use air conditioning to
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cool down indoor spaces, it kicks heat out into the outdoor spaces. So we experience something called the heat island effect.
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This could be sometimes 10, 12 degrees
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higher than when you don't have air conditioning units that are pumping hot air
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outside, is that right? Can using air conditioning inside raise the temperature outside by 10 or 12 degrees Celsius? Heat island experts assemble that's not quite right.
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So there is such thing as the urban heat island effect and the sort of driving mechanism for that is solar rating radiation.
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That's Dimple Rana, a heat specialist at design and engineering consultancy Arup.
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What happens is that during the day the sun shines onto cities and is absorbed by the fabric of the city. Things like our buildings, our roads, all of those things, they absorb solar radiation during the day and they emit that back at night, so you get that sort of heating effect. Air conditioning does contribute to this, but it isn't the driving factor.
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A
The heat island effect means cities are hotter compared to open countryside nearby. But this is mostly about how long it takes a city to cool at night when the sun goes down. Heat that's been absorbed by buildings and roads, most of which have lovely dark, non reflective colours, is radiated out into the environment. In a city, this heat doesn't go straight up in the sky. Some of it hits another building or road which absorbs it, slowing down the whole process.
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All objects are also emitting radiation and they also absorb it.
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That's our second expert, Sue Grimmond, a meteorology professor at the University of Reading. If you were to lie on the
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ground and look up, how much sky can you see?
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If you can see a lot of
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sky, then things are going to cool down very rapidly. And if you can not see very much sky, then they're going to cool down much more slowly because the radiation is basically being re radiated back to the surroundings.
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Another big factor in the heat island effect is what's going on in that sky.
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So clear skies, gentle breeze will be
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very large urban heat islands.
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If it's windy or, or cloudy, the urban heat island will be smaller.
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That's a very simple introduction to urban heat islands. And they can create very big differences in temperature between the most built up areas in cities and nearby countryside if the conditions are right.
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E
So I have seen that kind of figure of 10 to 12 degrees in some research and literature, but it varies. So our own work, we use our own tools to model the urban heat island effect. The biggest sort of urban heat island that we saw was about sort of 7 to 8 degrees and that was during the 2022 heat waves for Madrid.
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A
And what I hear you shout about air conditioning, Professor Rodriguez seemed to say on Channel 4 news that the whole heat island was produced by aircon and that's just not right. You can see that by looking at a city without much air conditioning, such as London.
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E
Yes. So there would be a heat island effect if we didn't have any air conditioning, for example, in London. We certainly have an urban heat is our own studies found it to be around 4 or 5 degrees and that's to do with the way that we design and build our cities. So it is all those kind of hard surfaces that absorb solar radiation during the daytime and re radiate it at nighttime, and that's the predominant effect.
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However, it is true that air con units pump out heat into the city. If you're in a business district in a big city, somewhere hot, with loads of very tall office buildings around you, it might make a difference of a few degrees. Although the research on this is limited, it might be even more if you're down the alley where the air con exhausts all come out. But if you're not, and it's daytime, the difference will probably be tiny. Here's Dimple's very ballpark estimate.
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E
I mean, maybe a fraction of a degree or a degree, depending on the size of the city, the amount of air conditioning, what temperatures you're cooling to, how many buildings are being air conditioned, there's lots of sort of variation in that, but yeah, I think solar radiation is probably the main thing.
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A
Of course, if your aircon is powered by fossil fuels, then in the big global sense, it is not good for climate change. But it isn't, as Professor Rodriguez said, responsible for raising the temperature in cities by 10 to 12 degrees. Our thanks to Dimple Rana, Sue Grimmond and to Professor Geoffrey Levermore and Richard Miller, who helped us with this report. Now, in the finale of our Unplanned Whales series, we got our part Welsh wizard Lizzie McNeill to scour the World Wide Web for any suspicious looking stats. What did you find, Lizzy?
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Well, there was a lot, but I think this figure about whales and carbon capture stuck out the most with a headline claiming that Wales could capture 1.7
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billion tonnes of CO2 a year. Wow. Seeing as the UK aims to capture just 20 to 30 million tons of CO2 by 2030, that's a stunning number. How on earth could Whales achieve that
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feat, that's through pooing.
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Excuse me, sorry.
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That's Dr. Olaf Meinecke. He studied whales for years.
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There's this complexity of behavior and the difficulty in predicting their behavior, and I guess that makes it really interesting. Plus, we're working in an extremely challenging environment, the ocean.
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He actually co authored a paper with a team from Griffith University in response to the media hailing whales as the next big thing in fighting climate change.
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Lizzie, can we backtrack a second? When I asked you to look for facts about whales, never mind. What was the full headline and where did it come from?
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D
So it came from Euronews and the article looked into a report by the International Monetary Fund and the full headline
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is Restoring whales to their pre hunted numbers could capture 1.7 billion tonnes of CO2 a year.
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And the headline of the IMF report is Nature's Solution to Climate Change.
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Wow.
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I am now completely invested in this story, particularly the idea that the International Monetary Fund's suit and briefcase army are now campaigning to save the whale. What did the IMF report say?
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So the IMF report looked at various scientific studies to try and calculate what a whale's worth is in monetary terms in the fight against climate change. The report concluded that great whales could capture 1.7 billion tons of carbon a year.
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Now, you say great whales, obviously all whales are excellent, but what makes a whale particularly great?
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D
So, yeah, these are just basically like big whales. So baleen whales, like blue whales and humpbacks and toothed whales like sperm whales. Now, this paper is based on recovering the whale population from its current 1.3 million back to its pre whaling number, which is thought to have been around four to.
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A
Okay, I now have this utterly improbable scene in my head of sperm whales magically appearing, flying back down through the atmosphere, repopulating our seas, you know, especially the crinkly bits. But then they immediately work together to get rid of 1.7 billion tons of carbon from our atmosphere. It's dizzyingly exciting. And perhaps that's just the wind.
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D
You done?
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Yeah.
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Okay, so we've said the IMF has scaled the whale population up to their pre whaling size. Then they assumed that each whale stores 33 tons of CO2 through their lifetime and that this carbon vanishes once they die.
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Is that true?
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No. Olaf wasn't a fan of this take. He thinks it overgeneralises because the study is based on one species of whale, not all whales, and it doesn't take into account carbon that whales release through breathing metabolising. Being metabolised and rotting. So he says, overall, the amount of carbon stored by whales after they die is negligible in the grand scheme of things.
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A
So whales don't hold their breaths all their lives and they don't necessarily sink to the bottom of the sea, get buried when they die.
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D
No, but the main part of the 1.7 billion figure actually comes from something else, phytoplankton.
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F
So that's based on calculations on phytoplankton, because the other components are quite small, you know, like the body mass. If we compare that to species like copepods, like these small crustaceans, it's insignificant. The point is that the phytoplankton is the major driver.
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A
Phytoplankton isn't a species of whale, is it?
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No, it isn't. It's a tiny marine algae, and algae spread to synthesise, like plants.
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So they take in CO2 and they release oxygen.
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Yeah, well done. So it's one of the main reasons why the ocean is such an important carbon sink.
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So where do the whales fit in?
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That's through pooing.
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Ah, yes, sorry, you did say that earlier.
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Basically, the way that whales can help boost phytoplankton is through fertilising them. Like farmers adding manure to crops, whale poo can add important nutrients to nutrient poor areas of the sea. But Olaf thinks that the IMF paper attributes way too much phytoplankton carbon cycling to whales.
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And we've seen that there is large variation between species. So not every whale poos the same poo, and they feed on different prey, and that influences, obviously what comes out. And the phytoplankton is fueled by certain trace elements, such as iron, and we found that there is differences in iron content between species.
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D
The IMF also assumes that phytoplankton stores this carbon forever, whereas 99% of it actually gets cycled or released back into the environment.
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F
Only about 1% of the phytoplankton, which is the primary producer, and they are the ones who actually capture the carbon from the atmosphere, only 1% of them are sinking to the bottom of the ocean and will be basically sealed up in that environment. In the ocean, on the bottom of the ocean, most of it is recycled and circulates at the top of the Ocean.
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Of that 1% that sinks, whales can't claim much credit.
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F
And then when we calculate what whales would contribute, of course that is a very small amount. And unfortunately, I mean, I would love that if whales could be the solution to our problems, they are probably in other ways, but not for the carbon sequestration.
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A
Okay, so Most of that 1.7 billion figure is actually temporary storage. We're talking days to decades, not a permanent solution. And while whales play a vital role in the marine ecosystem and our seas probably would be healthier if there were more of them, the idea that they're a solution to climate change is infinitely improbable.
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D
Yeah, unfortunately, we must throw in the towel of whale based climate salvation.
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Lizzie, never throw in your towel. We are a program that, that always knows where our towel is. You're listening to more or less loyal listener Louis Strong recently got in touch to ask us about something he had seen online. Hi More or less. The German filmmaker Werner Herzog recently posted this Instagram video. In it, he claims there is a remarkable pattern to the prime numbers. What's really going on here? Here's what Herzog I've been fascinated by prime numbers. No, I've been fascinated by prime numbers since two and a half thousand years. It's an unsolved puzzle among mathematicians. And now, not very long ago, mathematician Stanislav Ulam put all numbers in some sort of a spiral. And if you only highlight the prime numbers with black dots and you put them in the beads image, all of a sudden there's something very strange. Diagonal lines appear. They cannot be random. So what is the deal with prime numbers? To find out more, I spoke to mathematician James Grime, one of the stars of the YouTube channel Numberphile. Welcome back to More or Less, James. So let's start with the basics. What are prime numbers?
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Prime numbers are the numbers that are greater than one that are only divisible by one and itself. So 2, 3, 5, 7, 11, 13. And the rest, they are considered the building blocks of all other numbers.
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A
Excellent. So what does Werner Herzog mean when he says that there is a pattern to the primes that we don't understand?
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G
So primes are unpredictable and they kind of turn up in an unpredictable way. They're a bit like weed. Sometimes you get a couple coming very quickly in a short bunch, and then sometimes there's larger gaps. But they aren't just completely random. There is structure to be found in the primes.
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A
This seems like a good time to talk about Ulam spirals. Okay, so Stanislav Ulam, brilliant mathematician, physicist, nuclear bomb, I seem to remember, was involved with all of those shenanigans and he got bored in a meeting one day and started doodling. And what happened next?
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G
He took a piece of squared paper and in the middle of this piece of squared paper, he wrote a 1, and then he wrote the rest of the numbers 2, 3, 4 in the squares on this squared paper going around that center number one in a squared spiral going anti clockwise. So you keep going until you've filled up your squared paper, and then you shade in the prime numbers. So you started to notice that the prime numbers started to sort of form lines, diagonal stripes in this squared spiral.
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A
And I mean, are we talking about an absolutely predictable pattern here or just there's kind of a tendency for them to line up.
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G
It is a tendency to line up. So some of those stripes in this spiral we know will not contain primes. So some of those stripes will contain even numbers only.
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A
So by definition can't be prime minimus,
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which means that all your prime numbers have to go on the other lines.
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A
But the interesting thing is that the primes on those other lines aren't evenly distributed. Some have a few primes on them here and there, whereas others are really densely packed with primes.
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G
And this is still a mystery to mathematicians. So we think that we can explain how dense the stripes are going to be, but we haven't actually proven that that is a conjecture. So we know that some stripes are going to be more dense than others, but it's not a proven result.
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A
Okay, so that's a mystery. It's not as big a mystery as the Riemann Hypothesis. Tell us about that.
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G
Yeah. So Bernhard Riemann's very interesting, a very talented mathematician, but wasn't actually working in number theory. He did one paper in number theory. Just turns out to be the most important mathematical paper in number theory there's ever been.
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A
Sorry, dear listener, I would love to explain the Riemann Hypothesis, but we don't have time to even scratch the surface. Which brings us back to our listener's question. Despite all the conjectures, hypotheses, and spirals, do we have any idea what's going on with prime numbers?
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G
I think there's an inherent unpredictability in the primes. So what we see by looking at the Ulam spiral is some structure in the primes that you might not expect, especially if you were comparing it with just random numbers. It's showing us that primes are not just random. I hope that by looking at this image, it kind of inspires you to consider those problems, what we understand about primes and what we don't understand about primes.
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A
Our thanks to mathematician James Grime. And that is all we have time for this week. But please keep your questions and comments coming in to more or lessbc.co.uk. we will be back next time and until then, goodbye. More or Less was presented by me, Tim Harford. The producer was Tom Coles with Nathan Gower, Josh McMinn and Lizzie McNeil. The production coordinator was Siobhan Reed. The programme was recorded and mixed by James Beard. And our editor is Richard Varden. So, Alice Loxton, I'm here for the history.
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D
Well, Ben Henderson, I like the formality and that's perfect because we have a lot of history to share. Why did tea become such a British obsession? How did English turn into the language we speak today? And, yes, why do women's clothes still not have pockets?
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Well, in our new podcast, Here for
- [28:15]
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the History, we're investigating how stories from the past shape everyday life today.
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Basically, the things we've all noticed but
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never stopped to question.
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Listen on BBC Sounds or watch on YouTube.
- [28:26]
F
Just search for here for the history.