BRISTOLIANS think of themselves as different. Theirs was the only city to vote to adopt an elected mayor in a series of plebiscites held in 2012; nine others rejected the idea. The place has its own currency, the Bristol pound, which can be used in local shops and even to pay council tax. And it is unusually prosperous. The Bristol city-region, which includes three other councils (North Somerset, South Gloucestershire, and Bath and North East Somerset), has by far the highest productivity of any big conurbation outside London (see chart). It also has the highest household income beyond the capital.

Now George Osborne, the chancellor, has dangled the carrot of building on that success as part of his plans to devolve more power to city regions. In his budget speech on March 16th he announced proposals for a “West of England” mayor, who would govern an area joining up the four councils of the region. The offer is well-timed for Bristol, whose productivity advantage over other cities has been slipping, partly as a result of squabbling among the different councils.

Much of the city’s prosperity dates back to the slave trade, which accounted for half its income in the 18th century. Banks and insurance companies sprang up to support it. Even after slavery went away, the bankers did not: today Bristol has one of the highest concentrations of finance jobs in the country.

Happier factors also explain Bristol’s success. An hour’s drive from the beautiful architecture of the city centre are lush Welsh valleys. Bristolian companies are particularly inclined to let their staff work from home, suggest data from the Centre for Cities, a think-tank. This helps to explain an exodus from London of working-age folk, particularly those with families: in 2014 one-third more 30- to 50-year-olds moved from London to the Bristol area than vice versa. Graduates make up 46% of Bristol’s working-age population, compared with a national average of 36%. Foreigners like the place, too; immigration has boosted the city’s population by 6% during the past decade, one of the biggest increases in the country.

Bristol’s success is thus partly down to historical and geographical accident, but local officials have also taken some wise decisions. When the city received money to develop an “enterprise zone” offering financial relief to firms, the council located it in the city centre, next to the main train station. This was an unusual move: cities tend to use such grants to create business parks or manufacturing centres in struggling out-of-town areas. However, rapidly growing firms usually want to locate in buzzing city centres, points out Ben Harrison of the Centre for Cities. By supporting and encouraging more of them to locate there Bristol is playing to its strengths, he says. The council is also investing in snazzy new digital technology (see article).

But in other ways government has hindered more than it has helped. The lack of joined-up thinking among the four local authorities explains why public transport is so ropy. Friends of Suburban Bristol Railways, a pressure group, laments that at Bristol Parkway, another big train station, passengers arriving on the last train from London may face a half-hour wait for a bus. With cars the only option for many, it is small wonder that Bristol’s traffic is some of the worst in Britain.