It believes it can position the cities as an attractive investment for global businesses looking to diversify from struggling developed markets.

The stock market listing of Emaar, The Economic City, which is developing King Abdullah Economic City, demonstrates that many find the investment case attractive. The different specialisms of the cities offer a variety of opportunities.

The first cities, which have the highest profile and are in the most attractive locations in terms of investment, will find it easiest to attract the funding. Later ones might yet struggle. But the success of all the cities will undoubtedly be affected by how severe the global slowdown becomes, and how long it lasts.

Some investors feel that Sagia would have a much easier time attracting investment if the government took a stronger role in supporting the private sector in the cities.

This is the model that was used for the development of Jubail and Yanbu. Tellingly, the latest city development at Sudair will also receive government support for infrastructure development.

Ultimately, like any investment, it depends on a consideration of risks versus rewards. So far, the Saudi government has concentrated on offering rewards, such as generous tax incentives. Investors would be greatly reassured if Riyadh could also look at reducing the risks by offering subsidies and some guarantees of demand.

It is a brave move to develop all these cities on an entirely private sector basis. But in the current climate, it could be a step too far, even for Saudi Arabia.