It’s all too easy to talk about Britain’s north-south divide in the abstract, without really thinking too hard about what it means.

So, here are some numbers. On this graph, we’ve plotted the GDP per capita, at purchasing power parity, in England’s major northern cities. By way of comparison, we’ve included various other European countries, as well as London.

Funny how you never hear politicians mentioning that South Yorkshire’s economy is on a par with Slovakia’s, isn’t it? When was the last time anyone promised that, with a touch of hard work, the residents of Liverpool could have the same living standards as those plucky Czechs? Take London and the two regions that surround it out of the equation, in fact, and the UK economy is generating around €24,000 (£19,000) per capita. That was in 2011, though, so by now there’s a very real chance that it’s overtaken Spain.

Belatedly, efforts are afoot to fix all this. This morning, a coalition of northern councils published “One North: A Proposition for an interconnected North”. The report lays out plans to invest heavily in transport links between the great northern cities, making it easier for commuters, products and ideas to move between them. Result: economic powerhouse.

This is not quite as fanciful a notion as it might sound. To prove its point, the report points to two other European regions, which are made up of multiple cities but which are, in effect, one large economy .The Randstad region contains Amsterdam, Rotterdam, and most of the other major Netherlands cities, and houses a population of 7 million; further south you’ll find Germany’s Rhein-Ruhr (Cologne, Dusseldorf, Dortmund, etc), which houses 10 million.

Both of these are thriving economic units. There’s no reason the urban belt of 8 million that stretches from Liverpool to Sheffield couldn’t do the same. (That said, the inclusion of Newcastle, separated from the rest by 100 miles of open countryside, is a bit of an odd choice.)

What the Randstad and Ruhr have that the Transpennine region lacks, however, is decent transport. The continental megalopolises are linked by high-speed rail lines and glistening Autobahns. The cities of the north are linked by one rickety train an hour and the M62. So, here’s the One North wish list:

  • A frequent new high-speed (125mph) route across the Pennines, linking the cities to each other, to the region’s ports, and to the region’s biggest airport, Manchester;
  • More investment in local rail networks (metros, trams, etc) to link to the above;
  • Better freight lines;
  • A “digital infrastructure” offering “real time information” – what this means is not exactly clear, but it sounds suspiciously like a Citymapper for the North;
  • Building High Speed 2 sooner than planned, to connect all this to London and the south;
  • Extending the use of “smart motorways” which have variable speed limits and can bring in the hard shoulder to improve capacity at busy times (a technique known as Active Traffic Management);
  • Plugging gaps in the road network, particularly on routes towards Newcastle, which remains surprisingly poorly linked to the rest of the country.

All this would cost around £15bn, and take a decade and a half to deliver. It’s a lot to ask for.

But the idea that these cities could do more together than alone is one that’s wining a growing number of friends.  Jim O’Neill, the Manchester-born former Goldman Sachs economist heading up the City Growth Commission, has spoken in favour. So, more significantly, has the chancellor, George Osborne, who pointed out that it’s no more than the government is spending on London’s Crossrail, adding: “I think this kind of proposal is affordable.”

That north-south divide isn’t getting any narrower of its own volition: quite the opposite. It’s got to be worth a try.