Below a kebab shop in Shoreditch, at the end of a corridor covered with old Czech newspapers, an appointment-only establishment serves cocktails with a theatrical twist. Holy Smoke is essentially cognac, but comes hidden in a bible accompanied by smouldering frankincense and myrrh; Old Castro is rum poured over dissolving candy floss. Reviews of Lounge Bohemia on social media range from hip to hype.

Sustained by the well-paid workers of the East London tech scene, such bars are increasingly en vogue. They might not seem like an obvious magnet for productivity, yet some firms have located in or re-located to the area to recruit or retain the talented people who drink in them. A technology hub has emerged, which the government has branded “Tech City”.

The attraction of city living for the workers of the digital economy helps explain a shift in the innovation landscape. Rather than building on green-field sites, as the Silicon Valley pioneers did in the 1940s, a rising number of high-growth companies are choosing to locate and congregate in the core of cities, which offer advantages such as access to skilled labour and knowledge sharing.

“We are seeing the biggest rural urban migration in history,” said Peter Madden, chief executive of the Future Cities Catapult, a government-funded program to stimulate innovation. “Fashions have ebbed and flowed, but the last 150 years has been very urban.”

Competition for talent pits cities against each other: from Berlin, New York and Paris, to Beijing, Tel Aviv and even new upstart tech scenes such as Beirut. Investment brochures boast about a creative scene with art galleries, bars, restaurants and temporary “pop-up” installations. Eased visa restrictions, investment programs and direct incentives complete the offer.

This has led to a revived interest in business clusters – geographic concentrations of interlinked businesses – as a means of attracting mobile investment to stimulate growth. But building expensive out-of-town facilities would be unsuitable for footloose digital economy firms, many of whom require little more than a good internet connection. The new tools of economic development are downtown co-working spaces, and start-up incubators and accelerator programs.

Research by the Centre for Cities think tank and McKinsey, a consultancy, identifies 31 “economically significant clusters” in the UK: from financial services in London to Scottish whisky. Accounting for 8 percent of UK business but 20 percent of output, they are a “major contributor to growth”, and offer high salaries.

Centre for Cities Analyst Edward Clarke says it’s not possible to classify all of the 31 clusters as either urban or rural: many, such as Motorsports Valley in the Midlands, straddle large areas which include both. But he insists the most productive clusters “benefit from the fact that they are in cities”.

While fast-growing digital economy firms hog media attention, however, research-oriented firms in other industries – bioscience, for example, or motorsports – still require access to purpose-built facilities. “It depends where the focal point or the node is,” says Nigel Walker, head of access to finance at the Innovate UK agency. “Shoreditch is a village with artistic flair, and that wouldn’t work on a campus. But something that needs access to experimentation facilities, then maybe a campus is necessary.”

Governments continue to invest in them, from Russia’s Skolkovo Innovation Centre on the outskirts of Moscow to the Paris-Saclay research facility. Successful sites bring researchers, or people with ideas, together with entrepreneurs to turn those ideas into businesses, and access to finance. They also have good connection links to other centres.

In 2011, the government awarded the British Bioscience Research Council £44m to invest in its Babraham Research Campus, on the outskirts of Cambridge. Dr Celia Caulcott, its executive director for innovation & skills, explains that the campus is designed to attract small bioscience companies through access to world-leading researchers and facilities.

“It’s about proximity to discovery,” she explained, during the Innovate UK conference in London earlier this month. “We have invested to make sure that great research facilities are available to small companies that couldn’t possibly afford access to those things on their own.”

The flexibility of accommodation on the site appears to have given it the “stickiness” that economists crave. Will Spooner, chief science officer at Eagle Genomics, says the company has occupied seven different offices in six years on the campus as it expanded from 3 to 22 people: as the company grew, the space it occupied could grow with it, without the upheaval of moving to a completely new site.

Innovation, of course, doesn’t stop at city borders. Two “growth areas of national importance” attached to London – the Thames Gateway and the London-Stansted- Cambridge- Peterborough areas – extend far beyond the M25. Both schemes bring together policy makers across institutional boundaries, in an attempt to create joined-up thinking on issues such as transport, housing, and skills.

Public policy “should not only be one answer centric,” says Michael Joroff, a senior lecturer at the MIT Dept. of Urban Studies and Planning. Or, to put it another way: “A lot of growth will happen where growth happens.”