A part of the eternal magic of sports, the Olympic Games organisers and their multinational sponsors often put forward three arguments to justify the enormous expenditure of public money on hosting the Olympics, which for the London Games, cost more than €15 billion, according to a British parliamentary report, which is seven times more than budgeted for in 2005.

First, the argument goes, the Games have an immediate economic impact as hundreds of thousands of participants and tourists arrive. Moreover, the presence of thousands of executives from global companies creates abundant opportunities to attract investment. British Prime Minister David Cameron said last week that the Olympic dividend for the UK economy will come to nearly €16 billion.

Second, the Games and other major events make possible the rehabilitation of run-down neighbourhoods like the East End of London, where the stadium and the Olympic Village have been built. Barcelona '92 is often cited as the paradigm of the Games as catalyst for urban renewal.

And third, given the epidemic of obesity affecting societies growing increasingly sedentary, the sculpted abdomens of athletes like Jessica Ennis or Usain Bolt can only encourage people to get more exercise.

Reality check

“Which is odd, because, in all the studies, none of those three correspond to reality,” says Mark Perryman, author of “Why the Olympics aren't good for us” (OR Books, 2012).

It may seem too blunt a statement, but only a week had passed in London before the first pro-Olympics factor was called into question.

Around 1.5 million foreign and British tourists visit London in August, and it is estimated that half may have decided not to come this year to avoid the logistical problems created by the Games, says Michael Burke, an economist with ties to former London mayor Ken Livingstone. This is only partially offset by an estimated 800,000 tourists who come to see the Olympics. “All the regular tourists have not come, and there will be a negative impact on the economy,” believes Burke.

The only firms that exceed their usual business this week in London are the international chains in the new Westfield Stratford City mega-mall, owned by an Australian real estate conglomerate, which was built next to the Olympic Park.

Nor is there much reason to think that the economic impact following the Games will be positive. In Greece, GDP growth was 1.5 per cent in the years leading up to the Games (1997 to 2004). Afterwards, however, that impact “collapsed, not to say vanished completely,” says Evangelia Kasimati, Greek economist at the University of Bath, who has just finished a report on the Athens Games.

Jobs wiped out

Jobs created to build facilities, provide security or guide people about do not last long. Within three months after the 2004 Games in Athens 70,000 jobs had been wiped out, mainly in construction, says Kasimati. The same will happen with the hundreds of thousands of guides, monitors and security guards hired at the last minute by private companies like G4S.

In the longer term, the Athens Games – “financed almost exclusively with public money,” recalls Kasimati – have had “a rather modest economic impact.” Many Greeks believe that the Games aggravate a culture of public profligacy that has become endemic in the Greek bureaucracy.

The iconic buildings and a new metro and tram network gave a lot of work to foreign companies such as Siemens and to star architects like Santiago Calatrava, but the cost to the taxpayer was astronomical: at least €12 billion, or four times the original budget. The Greek government, as part of its forced privatisation program, is now trying to sell some of the Olympic venues at knock-down prices.

The urban transformation model imposed by the Olympics is, at times, a world turned upside down. “In Athens, as in Sydney, it took a lot of work to find a use for the Olympic parks,” says Beatriz García, an expert in the Olympic Games at the University of Liverpool.

Regarding the transformation of London's East End, García is more optimistic than Sinclair or Perryman: “It will be a creative hub with opportunities for economic growth.” Over time, as happened in Barcelona, “a community will grow up around the Olympic Village and the new facilities.” But, as happened in Barcelona, there are some who wonder: what class of community will it be?

Nor is there much evidence that the third boost factor of the Olympics is true. “The evidence that the impact on public participation in sports is positive is merely anecdotal,” says the report 'A lasting legacy for London'. After the Sydney Games there was only an increase in practitioners of aerobics. After the Athens Games, there was indeed an immediate effect. However, it later dropped back and settled at its former levels.