T EESSIDE WAS the future, once. In the 1950s Ridley Scott, then a student at the Northern School of Art in Hartlepool, would walk down to nearby Redcar, crossing a bridge over the steelworks on his way. The view of the area’s bustling chemical plants, roaring blast furnaces and booming seaport inspired the opening shots of Sir Ridley’s 1982 film, “Blade Runner”, set in a dystopian 2019.

The future has arrived, and Teesside looks very different to the scenes Sir Ridley imagined. The industrial area around the mouth of the river Tees, where 40,000 people once worked, now employs just 3,300. Most of its buildings lie abandoned, including a blast furnace as tall as St Paul’s Cathedral that was closed in 2015.

Big plans are now afoot to reinvigorate the area. Last year a 4,500-acre industrial plot, rebranded as the South Tees Development Corporation, became Britain’s first “special economic area”, with the power directly to collect business rates on the site to fund land remediation work. More than £100m ($130m) of central-government grants have helped to redevelop the plot. Ben Houchen, the young Conservative mayor of the Tees Valley, says the next step is for the site to become a “free port”, with carve-outs from the national customs regime. The Treasury is considering the plan.

That too would be a first for Britain. Free ports and special economic areas are common elsewhere in the world. There were more than 4,000 in 2015; a report in 2008 estimated that up to 68m people worked in them. Simon Clarke, the Conservative MP for nearby Middlesbrough, raves about Jebel Ali, a free zone in Dubai through which a quarter of the emirate’s trade passes. A special economic zone near Hong Kong, set up in 1980, has been dubbed the “miracle of Shenzhen”. Policies tested there have spread to other Chinese cities. America launched “opportunity zones” in 2017, which do away with capital-gains tax for firms investing in poor areas.

The idea that Britain could copy these was outlined by Rishi Sunak, another local Tory MP, in a paper for the Centre for Policy Studies, a think-tank, shortly after the vote to leave the European Union in 2016. Mr Clarke and Mr Houchen argue that Britain should establish free ports nationwide, as a cure for long-term industrial decline and any trade friction caused by Brexit.

Companies are interested. Two metalworks firms have promised to build factories on the Teesside plot, helped by £14m from the central government to prepare the site. PMAC , a Yorkshire-based business, has signed a £250m deal to build a waste-to-energy plant there . And in November a consortium of six big energy companies announced plans to build a gas-powered energy plant, claiming it would be the first in the world to use carbon-capture technology on a large scale.

Economists tend to be sceptical of free ports. By design they create distortions. Cutting taxes in one place encourages firms to move there, but at a cost to other regions. “Enterprise zones”, British forerunners to special economic areas, were found mainly to attract relocating firms, rather than new ones.

Mr Houchen says Teesside can avoid this by focusing on industries without a large presence elsewhere in Britain. He claims the firms investing there would “come to Teesside or not to Britain at all”. That might not solve the problem. Economies operate in equilibrium, says Meredith Crowley, an economist at Cambridge University. A benefit offered to one firm causes relative harm to another. Firms operating in a free port could undercut those outside.

The policy becomes costly over time, as tax revenues are forgone. Special incentives may cut $3bn from Amazon’s tax bill at its new base in New York, which critics say it would have built in America without giveaways. The same idea may apply in Teesside. Chris McDonald of the Materials Processing Institute, a research and advisory firm based there, says that industrial companies need land, power, ports and people, all of which are abundant. As Mr Houchen says, “Once you get people here, they see the other benefits of the site and invest.” If you build it they will come—but they may have come anyway.