system
Given the following post, respond as if you're commenting on Reddit:
human
Why is the UK so economically dominated by London?

I get the impression that the UK's economic activity is particularly skewed towards London, with the rest of the UK lagging behind a lot. Other countries often have strong centres of economic activity outside their capital city. 

This seems to cause a lot of problems (high house prices and overcrowding in London, a feeling of left-behindness elsewhere) so I would be interested in knowing why it's happening.
gpt
I can answer this as somone who has studeied the UK's history and lives here.

The UK's north south divide started to become apparent in the interwar period. This is for several reasons. The north had iron/steel works, ship building and other heavy industry like coal mines. However, these industries went a long painful death that saw the economies of that area go down and down. The Great Depression exacerbated this. Northern Towns suffered higher rates of unemployment and economic deprivation. Jarrow, a ship building town, saw roughly 80% unemployment. 

In Comparison, London was the financial capital of the world. Britain's trade decifit was only pallatable due to the export of financial services to the rest of the World. Britain has only increased this divide as globalisation has brought in new markets for its financial services alongside deindustrialistion and the fact that the coal mine and industry of the north has lost either its market or profitbility.