CITIES HAVE often bounced back from crises. From pandemics and earthquakes to floods and fires, the world's urban powerhouses have emerged stronger when faced with adversity. After the Great Fire of London destroyed most of the city in 1666, a raft of fire safety regulations were ushered in. Builders swapped timber for brick or stone. Walls were made thicker. Streets became wider. When cholera tore through America in the 1850s, New York and other cities introduced sewage systems and public parks.

Today's urban areas face a challenge of a different sort. With the mass return to office work still uncertain, the pandemic has sharpened debate about what the future holds for their commercial hubs. Key business districts like Manhattan, the City of London, Tokyo's Marunouchi and La Défense in Paris have borne the brunt of the office exodus. Before lockdowns, the 21 largest business districts in the world housed 4.5 million workers and around a fifth of the headquarters of Fortune Global 500 companies, according to EY and the Urban Land Institute. When Covid-19 emptied offices around the world, most professional work shifted to home offices or kitchen tables. As the pandemic stretches into a third year, the fate of business districts remains unclear. Can they continue to attract investment and talent, or will new work patterns jeopardise their commercial dominance?

On the face of it, things could have been worse for the owners of gleaming city office towers. Unlike the retail and hospitality sectors, office tenants have mostly continued to pay rent and analysts have retracted many of their worst projections. Leasing activity even picked up in cities like London towards the end of 2021.