For any city contemplating bidding for one of the great international events, like the Olympics, the Fifa World Cup or Expo, the buzz-word is "legacy".
It is an honour to stage such an event, of course, and the chosen city or country can bathe in the light of international exposure. A successful event will lift the spirit of the nation, giving it an air of self-confidence, along with the revenues from the millions of visitors to the event.
But the people who put the bids together - and it has become quite a specialised profession - are also conscious that there has to be a more lasting effect.
It has to be demonstrated that the event will bring long-term economic and social benefit. That is the "legacy".
Perhaps this is because of some of the great financial disasters that have been associated with such events in the past. The Olympiads in Montreal in 1976, and Athens in 2004 stand out as textbook studies of how not to organise an international event, costing the hosts billions of dollars that can never be recouped.
Expos are smaller and less permanent, and therefore are not as expensive as staging the Olympics. But they are still significant financial undertakings. It is estimated the Dubai bid will cost the UAE about Dh30 billion.
This time last year, London was in the middle of preparations for its own Olympiad, which turned into a huge celebration for the British capital. The event was judged a success by sporting and reputational standards, with the British team bagging a stack of gold medals.
The British government has recently published a financial equivalent of the medals table, and it looked as though Britain won again. The figures showed that £9.9bn (Dh55.77bn) had flowed into the country in trade and investment as a result of the Games, which outweighed the £8.7bn cost of the event met by the government.
The organisation that made the calculations identified £5.9bn of trade and business deals that were clinched at a special business event during the Games, as well as £2.5bn of inward investment and contracts worth £1.5bn signed with countries such as Brazil and Russia that bought British expertise to help to stage their own forthcoming events.
So the Olympics had made Britain a profit of £1.2bn. Or had it?
No sooner were the government figures published than economists and other experts began to declare that the methodology was unsound.
The figures included virtually any project that was announced in London around the time of the Games, some many miles away from the main Olympic sites.
How much of the benefit would have come through anyway, even without the Olympics, they asked?
And what of business lost by other companies not involved in the Games? Many complained bitterly that they had been excluded from possible deals by the British government's insistence that Olympic sponsors were given preferential treatment.
Another report into the economic effect of the Games for the United Kingdom suggested that up to £41bn might be generated from the event in the 16 years up to 2020. This too was criticised by academics for uncertain methodology and for adding in large sums of money after the Games had finished.
The financial risks of an Expo event are not as great as an Olympics or World Cup, it must be pointed out. Capital funding for the 2020 bid is estimated at a relatively modest ?5.2bn (Dh25.17bn), while operating costs will be covered by ticket sales and other forms of commercial exploitation, the bid documents state.
And the 438-hectare site where the Expo would take place (if Dubai wins) looks to be a strategic trading location, close to Jebel Ali port and the new Dubai World Central airport. It should be a valuable addition to the emirate's commercial infrastructure.
Nonetheless, Dubai should scale back its expectations of "legacy". The economic argument is never conclusive, as the debate in London shows. It will be legacy enough for Dubai to win, and stage, a successful Expo.
fkane@thenational.ae
