Skyscrapers get a bad rap but are crucial to the success of cities, writes economics professor Jason Barr.

Skyscrapers remain controversial in the 21st century, yet they are getting taller and more numerous. Seven times more buildings of 150 metres or taller have sprung up since 2000 than were constructed in the entire 20th century. Five decades ago, the height of the tallest building completed each year globally averaged around 250 metres (55-60 storeys). Nowadays, they are typically double that height.

Since the birth of the skyscraper at the end of the 19th century, critics have argued that the tall building takes more from society than it gives in return. Many an architect predicted their eventual demise, including Frank Lloyd Wright, who later returned to the fold in 1956 with his mile-high prototype for Chicago.

Height limits eventually fell by the wayside as cities realised they caused more harm than good

Around the turn of the 20th century, cities frequently banned skyscrapers. By 1921, at least 22 US cities – including Chicago – had height caps. In 1894, London restricted buildings to 80 feet (24 metres) tall. Yet height limits eventually fell by the wayside as cities realised they caused more harm than good by restricting the construction of needed buildings.

When New York City took a different approach in 1916 by regulating building shapes through setback rules, and its skyline mushroomed in the Roaring Twenties, global cities learned a lesson: great cities need tall buildings to help them thrive. At the end of the century, London, too, realised it needed tall buildings and reversed its earlier rejection of them.

To see why this is so, we must take a step back and ask a broader question: why does the growing majority of the world's population live in cities? The fundamental answer is markets. Cities are, first and foremost, labour markets, where people find their jobs. In this sense, cities are the engines that power our economic lives.

For example, the three most productive counties in the US: New York County (Manhattan), Los Angeles County, and Cook County (Chicago) combined generate 9 per cent of the US gross domestic product (GDP), yet they use 0.18 per cent of its land mass. London's GDP accounts for a whopping 22 per cent of the entire UK economy.

People come for the jobs but stay to experience all that a city has to offer, be it culinary delights, art and culture, educational opportunities, or to enjoy each others' company. Even working from home (WFH) will not drive us out of the city. Yes, WFH is causing some relocations and adjustments, but in the end, the economic engine that powers our society – cities – will continue to hum.

Given the city's vital importance in our lives, how should it be organised to function best? The answer is through the land market. As nicely summarised by urban planner and author Alain Bertaud, the land market "provides a strong incentive to users to use as little land as possible in areas where there is a strong demand".

The skyscraper is a geography-shrinking machine

High land values signal the value of geography, indicating that more people and businesses want to be in the same place at the same time. The skyscraper is thus a geography-shrinking machine. It pinches the ground to squeeze out new land – land in the sky – satisfying the wants and needs of hundreds, if not thousands, of people.

While tall buildings serve a vital purpose, they can generate negative unintended spillovers, such as shadows, greenhouse gases, or a feeling that they harm the streetscape. However, the solution to these problems is not to ban tall buildings, as today's critics frequently urge.

Rather, the rational approach is to create policies that incentivise improvements without eradicating the benefits. Just as important, we need to recognise that skyscrapers are one element of the built environment and that the metropolis is an intertwined system of real estate, transportation, employment, and quality-of-life components.

Housing affordability: the answer to expensive housing is to flood the market with new units – throughout the entire city. The reason so many luxury high-rises appear in the centre is both because of international demand and because there are so many restrictions preventing new housing outside the centre.

Those who try to prevent even moderately taller buildings in their neighbourhoods are incentivising more high rises in the centre than there would be otherwise if housing supply opportunities existed more broadly throughout a metropolitan region.

Greenhouse gases: because of their size, skyscrapers generate more carbon emissions per square metre than smaller buildings. Critics of tall buildings look to Paris as a model of the well-designed, low-carbon city. While it's true that five- to ten-storey buildings are best in terms of minimising greenhouse gas emissions, it does not logically follow that they should be required by fiat.

The real problem of modern cities is that too many automobiles take up too much urban land

If you look at Paris' global ranking in terms of its importance in the world economy, as measured by the size and number of international firms, it's falling. Paris in 2000 was ranked fourth, and by 2020, it was down to eight, losing out to skyscraper cities such as Singapore and Dubai.

In the last decade, Paris has shrunk by 122,000 residents. As reported by Forbes, "Many of those leaving are choosing either the suburbs or countryside around Paris, or they are relocating to France's smaller cities such as Bordeaux, Lyon, and Toulouse." By limiting its building stock, Paris is driving up housing prices, pushing out residents, and causing suburban sprawl.

More broadly, we all go about our lives, flying to our vacation destinations, driving to work in our automobiles, and turning on the heat when we are cold, but few claim we should ban aeroplanes, cars, and heating units. The solution is to tax carbon production, switch to green energy sources, and incentivise industries to create more energy-saving technologies.

New York and London have regulations penalising developers for generating excessive amounts of carbon. This is the right policy and should be expanded to all property owners.

Street life: tall buildings have been criticised for destroying street life. Yes, sometimes these buildings can feel overwhelming. However, city planning and urban design that prioritises pedestrianism can then incentivise buildings that better engage with the street. The real problem of modern cities is that too many automobiles take up too much urban land. Reducing car usage and opening public spaces are the real drivers of urban vibrancy.

Great cities have skyscrapers because they allow us to live, work, and play together. This is not to say that tall buildings belong everywhere or that all cities need them. But they do serve an important purpose. When we listen to the land – when we let the value of geography speak to us – skyscrapers can rise in the right place at the right time.

Jason M. Barr is a professor of economics at Rutgers University-Newark. His new book, Cities in the Sky: The Quest to Build the World's Tallest Skyscrapers, is published by Scribner Books.

The photo is by Jonathan Roger via Unsplash.

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