Here is an excerpt from a Guardian article that was published last year (by Tim Burrows) about Grimsby, England:
In Grimsby’s 1930s heyday, fishermen used to head to Freeman Street as soon as they were off the trawler, straight to the Lincoln or the Corporation Arms to spend their bountiful earnings. A century previously, Grimsby had been a fairly sleepy fishing village, but by the 1890s it was on the way to becoming the biggest fishing port in the world. In the mid 20th-century, trawlers were bringing in 500 tonnes of fish a day.
Today, Grimsby still has a thriving indoor market (paid for by the EU and the Enrolled Freemen of Grimsby, an organisation that dates back to the 13th century), but the further north towards the docks you walk, the emptier and more dilapidated things get. A local businessman says sex workers wait around at night for lorries to take them to the deserted docks. “It’s a legacy of the old fishing days.”
There is scant legacy to be found elsewhere. After a long decline, the fishing industry died in the mid 1980s, its owners selling their trawlers to companies in Aberdeen or Japan. Unlike Hull across the river, currently basking in its year as Capital of Culture, Grimsby is the Humber city that never was.
More than 70% of people in Grimsby, England voted to leave the European Union in the 2016 "Brexit" referendum. It was one of the highest shares in the country. But with one of the highest unemployment rates in the country, that outcome is not all that surprising.
Supposedly, at its peak, there were eight onshore jobs for every one at sea in Grimsby. And like all thriving cities, there were economies of agglomeration, which resulted in things like the largest ice factory in the world. The fishing fleets needed crushed ice -- and lots of it.
The Grimsby story is, of course, not a unique one. You just have to replace fishing with some other industry. Many cities have managed to diversify their economies either out of necessity or because they saw the writing on the wall. But for others it has been a real struggle.
It's one of those things that is perhaps simple, but far from easy.

The European Union uses something called the Nomenclature of Territorial Units for Statistics (or NUTS) in order to geographically subdivide its member states and collect statistical data. There are three scales: NUTS 1, 2, and 3. And generally speaking, they follow existing administrative boundaries. Or at least that's the goal.
In addition to being used for collecting statistical data, they also form the basis for how the EU implements its "cohesion policies", which are designed to direct funds toward less developed regions within the Union based on GDP per capita (PPP).

Because these NUTS impact funding allocations and because they can be redrawn if certain criteria are met, there's not surprisingly an incentive to gerrymander. The Pudding has a great visual essay that explains why this happens and how Hungary split its central region into two new ones, isolating its capital, Budapest.
Big cities tend to be, of course, more developed than their surrounding areas. But it is interesting to see by how much. Though an extreme outlier, the Inner London - West region has a GDP per capita that is 625% the EU average (2017 numbers).
Image: The Pudding

The United Nations recently released its 2015 version of World Population Prospects. It looks as if they put out and revise this report every 5 years.
The Economist then took some of their data and assembled it into the following charts:

It’s obviously extremely difficult to predict what will happen in the world by 2100, but to the extent that forecasting is possible, the world’s population is expected to reach somewhere around 11.2 billion people. Today it’s 7.3 billion.
The bulk of this growth is expected to happen first in Africa, and then in Asia. By 2100, Africa’s share of the global population is expected to grow to 39% and Asia’s share is expected to decline to 44%.
If you’ve been following population trends, most of this shouldn’t come as a surprise to you. The meaningful population growth happening in the world today is happening in the developing world.
That’s why architects, such as Rem Koolhaas, have been studying cities like Lagos (Nigeria) since the late 1990s and early 2000s. Below is a photo from a book/research project that I love called Mutations (2000). I pulled it from my bookshelf this morning.

It’s interesting to think about what all of this will mean for the global economy and for global governance.
The United States is about to be alone when it comes to advanced economies with a globally competitive population. Europe is shrinking, which leads me to believe that a strong EU is likely important. And we now have lots of megalopolises with big populations, but with very low income levels.
Nigeria is the largest economy in Africa, but per capita income is somewhere around $3,000.