Welcome to more or less on the BBC World Service, the programme all about numbers and statistics.

The Olympic Games and the Football World Cup, two of the biggest events in the world,

which are each hosted every four years, are big business.

And it costs a lot of money to host them. And a lot of the money comes from public funds.

When places bid to hold them, politicians, organizers and other officials sometimes use

big numbers to explain how hosting such an event will benefit their country or city economically.

There's an upward estimate of about 40 billion of where this could eventually lead to by the

end of the decade, but certainly a very considerable net benefit to the UK.

But how exactly do you measure the economic impact of a major sporting event on the host

city or country? In this week's edition of More or Less, will we finding out,

after all the sporting activities are over, how realistic were those economic predictions?

Economist Professor Andrew Zimbalist from Smith College in the US has studied the impact of

mega sporting events. It's practically a unanimous view that the hosting of mega sporting events

is either a neutral economic event or it's a negative economic event.

And generally speaking, the less developed the city is when it undertakes to host such an event,

the more money they have to spend and the more likely it is to be a negative event.

When governments bid to be a host country, they produce what's known as an economic impact study,

using models to predict how much more money might be generated. For example, will it bring more

jobs? Will people living in the area earn more money? If we talk about, say, the Olympics,

there's generally a claim that there'll be an increase in people visiting your city,

an increase in visitors, increase in tourists, who will spend money at hotels and restaurants,

and then there'll be a multiplier effect on other activities. They also say that if it's an event

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