The Blitz, the German bombing campaign against Britain during the Second World War, had a profound impact on London.
From September 1940, the German Luftwaffe dropped some 20,000 bombs on the city, killing thousands, and leaving many more homeless. But for all its human cost, a 2021 research paper has suggested that the London Blitz may also have had a significant impact on how the capital would develop in the years after the war.
Economists calculated that, had the Blitz not occurred, London’s Gross Domestic Product (GDP) would be 10% lower, or £50 billion worse off every year.
The secret of London's skyline
Voiceover: “The Blitz had a profound impact on London. From September 1940, the German Luftwaffe dropped some 20,000 bombs on the city, killing thousands and leaving hundreds of thousands homeless. But for all its human costs, new research has revealed that the Blitz also had some positive effects. Economists Gerard Dericks and Hans Koster recently calculated that, had the Blitz not occurred, London’s GDP would be 10% lower, or £50 billion worse off every year.
To find out why, we first need to take a look at London’s skyline.
London is a global city, a world leader in finance and business. But unlike many superstar cities like New York or Hong Kong, London's skyline is more reflective of the 19th century than the 21st. London has just 37 skyscrapers, compared to Hong Kong’s 554.
A key reason for that are London’s building height regulations; some of the strictest in the world. Here's Hans Koster to explain.”
Hans Koster: “Many places around the world have building height regulations and London is just one of them and the reason is to protect historic buildings. So if you have lots of build heritage then typically you're not allowed to build taller than these historic buildings. But areas that were heavily bombed then you don't see these height regulations being so important, there is nothing to protect anymore, and therefore the building height is higher in these places.”
Voiceover: “This is clear even from anecdotal evidence. London’s skyscrapers are concentrated in the area where Blitz bombing was heaviest – The City of London and the Docklands. Often the bomb sites of 1940 are the building sites of today. These areas were first rebuilt in the 1960s but the buildings, deemed unworthy of protection, were torn down and replaced with the towers that we know today.
But to empirically prove the link between the Blitz and building heights, Hans first had to prove that the distribution of German bombs across the city was random.”
Hans Koster: “So we want to show that these bombings were random and, well, we have lots of stories about this, right. The German airplanes they flew at night, they couldn't sort of hit anything within a 2 kilometre target. So they, they just randomly dropped this stuff over London. But also, like within a neighbourhood, we actually proved statistically that these bombings were indeed random. Some buildings were bombed some was not. It could have been otherwise.”
Voiceover: “Thus, Hans was able to prove that the Blitz bombing is correlated with fewer planning restrictions and taller buildings.
A clear example can be seen just behind Hans in Aldgate. This map shows bomb damage in London in 1945, purple meaning damaged beyond repair. Today, much of this area is now populated by high rise office space. But why all this focus on tall buildings? Why are they important?”
Hans Koster: “We see here behind us the tallest buildings of London and the, of course, host the the highest concentration of workers in the in the city, but also in the wider metropolitan area. So taller buildings lead to higher density. The main reason why density is considered to be sort of a good thing is what we call agglomeration economies. First of all you have access to like a highly skilled labour pool and there we have knowledge spill overs and these are key. So knowledge spills between these firms, they share information, and just by being close to each other they, they benefit from each other and they are more productive.”
Voiceover: “More productive firms make more money and that means that the most heavily bombed areas of London also house a much larger proportion of London's economy. And that's a big deal. According to the Resolution Foundation, UK productivity has grown by just 0.4% annually in the years since the financial crisis, less than half the rate of the 25 richest OECD countries. Could this new research provide the answer?”
Hans Koster: “So we had the Blitz and and the Blitz bombed like many parts of London and we see that on the sites that were bombed we see taller buildings today and these taller buildings are often concentrated and that leads to higher densities of buildings, and then we find that these higher densities are associated with increases in productivities. And if you add this complete effect together right, if you would not have the Blitz, productivity levels would then decrease by 10%, so that's substantial. I'm not saying that you should bomb cities, obviously not, let me be very clear about this. But it shows that the impact of building height regulations is quite strong and, particularly for like these superstar cities like London.”
Voiceover: “London currently has the most expensive office space in the world and planning restrictions are a key part of that. While this new research provides an interesting perspective on a dark and tragic chapter in British history, it also reveals the modern damage done by London's planning laws. Laws which, if altered, could help to solve the UK's productivity puzzle.”
Hans Koster: “The Blitz sort of provides us with this unique opportunity to see what the effects are of like having strong building height regulations. Sometimes, like, they protect beautiful built heritage and we should keep doing that. But sometimes they don't and then the question is whether that's the right thing to do, and probably we should be more relaxed in that respect.”
