For the last few years, one of the big ideas in the world of urbanism has been ‘agglomeration’: the theory that, when it comes to city economics, bigger is better. In a 2011 speech, the theoretical physicist Geoffrey West unveiled research showing that, the bigger the city, the higher its growth rate, and the faster it produced all sorts of helpful things like patents. (Also unhelpful things like crime, but who’s counting?)

All this presented Britain with a problem. London aside, none of its cities are that big in global terms. (The urban areas of Birmingham and Manchester just about sneak into the top 200.)

So in 2014, Britain’s coalition government came up with a plan. Between them, the urban areas of Manchester, Liverpool, Sheffield and Leeds have a population approaching that of London. By improving transport links within and between those cities, so the theory ran, they would be able to act like a single urban area, rather like Germany’s Rhine-Ruhr or the Netherlands’ Randstad – two other multipolar urban regions which are, pleasingly, rich. Finally, the north would be able to act as an economic counterweight to London and the south east. And all we had to do to make it happen was to build a new trans-Pennine train line that we probably should have built years ago anyway.

A lot of people loved this idea, for fairly obvious reasons. It meant a big new investment in transport in the north, rather than in London. The benefits would be shared by a number of cities, making it much easier to build support for the idea. Bored transport journalists would tweet out crowd-sourced maps of potential routes.

Liverpool-Warrington-Media City-Manchester-Halifax-Bradford-Leeds, with a branch from Manchester to Sheffield. Sorted. pic.twitter.com/To2QAQvrzL — Jonn Elledge (@JonnElledge) August 8, 2017

And yesterday, at a transport summit in Leeds, the region’s political and business leaders called on the government to honour its promise to build Crossrail for the North/HS3/the Northern Powerhouse Rail, the proposed new rail link which has been blessed with rather more names than funding commitments.

On the whole, then, it’s distressing to learn that, just possibly, we’ve all been wasting our time.

Paul Swinney is the chief economist at the Centre for Cities, and an occasional contributor to CityMetric. (Full disclosure: the Centre has sponsored us since 2015.) He’s a northerner himself – a good Sunderland lad – and a man who spends a lot of time thinking about how to rebalance the British economy.

And yesterday, he tweeted out a pretty convincing argument that the cross-north link is really not the biggest priority. It’s worth reading the entire thread – but here are the key points.

1. London’s situation is unique in Britain

Both wages and house prices in London are high. As a result, people will commute from very long distances to get to jobs in the capital, and making it easier to do that will produce a big economic benefit.

1. People commute long distances into London because wages are high (pull) & housing is £ (push). Not the case around northern cities pic.twitter.com/EoX7d98fYy — Paul Swinney (@Paul_Swinney) August 23, 2017

That logic doesn’t apply in most of the northern cities, where housing is affordable, and wages are lower, however. That means it’s more possible to live in the city, and less attractive to commute from elsewhere to get there.

2. Northern commuters aren’t going from city to city

People do commute into Manchester, of course: but they’re more likely to come in from the rural areas to the north or south, rather than the other cities to east or west.

3. Those that do commute currently don't choose to live in another city but in the countryside, because it offers something different pic.twitter.com/rsfVHfENHY — Paul Swinney (@Paul_Swinney) August 23, 2017

After all, if you want to live the urban lifestyle while working in Manchester, you might as well just live in Manchester.

5. So Manchester should instead be shouting for better commuter lines from its rural hinterland. Crossrail for Manchester. — Paul Swinney (@Paul_Swinney) August 23, 2017

3. Transport isn’t the big problem

I’m not going to lie to you, this one breaks my heart. But the numbers suggest we’ve all been stariing at the wrong problem:

7. Skills in northern cities look bad not just in a UK context pic.twitter.com/ZFbkQRSV76 — Paul Swinney (@Paul_Swinney) August 23, 2017

The data gets even more depressing when you look at the picture internationally.

8. But in a European one too pic.twitter.com/wjzu6YOu53 — Paul Swinney (@Paul_Swinney) August 23, 2017

4. ...so Crossrail for the North is a distraction

Finally, the government only has so much bandwidth (even more so, in the age of Brexit). The time and energy that goes into a big project like a new railway line is time and energy that isn’t spent fixing the region’s other problems.

Or to put it another way: perhaps my whole life I’ve been living a lie.

Paul’s prescription is that cities need devolution (so, in practice, mayors), so that they can tackle the skills gap and sort out transport problems within, rather than between, cities. It’s not the agglomeration theory is wrong, exactly: but weak transport networks mean that a city of 1m people will punch below its weight, simply because it can’t connect people with jobs.

In fairness, Jim O’Neill’s Cities Growth Commission, which kicked off much of this debate back in 2014, made many of the same points. HS3, or whatever we’re calling it in this paragraph, was never meant to be a panacea, but part of a much bigger package of investment in both transport and skills.

So how did the debate come to focus on this one grand projet? I suspect the answer is jam-spreading. Pouring money into a tram network for Leeds, say, would get backs up unless it was accompanied by similar investments elsewhere.

A new trans-pennine rail link, though, would seem to benefit a lot more people: that makes it easier to sell. It feels significant that Newcastle – a very long way from the four other big northern cities – ended up folded into the Northern Powerhouse scheme, simply because it was too awkward to exclude it.

None of which is to say that HS3 (I’m sticking with that name) is a bad idea: the existing trans-pennine links are shocking, and it’s pretty gross that transport secretary Chris Grayling scrapped plans to invest in rail in the north in literally the same week he called for another £30bn railway line for London. But if money is scarce, there may be better things we can do with it.

You can read more on this subject in “Building the Northern Powerhouse”, a report Paul Swinney produced for the Centre for Cities in 2016.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason.

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