SKYSCRAPERS aren't the only thing sky-high in Hong Kong. Rents for high-end flats of the type commonly let by expatriates are the most expensive in the world, at nearly $12,000 a month. ECA International, a human-resources consultancy, compiled the ranking, which looked at rents of comparable apartments with similar proximity to international schools, embassies and "social focal points". Geneva and São Paulo both climbed six places up the table from their positions last year, as rents shot up around 30% in 12 months. But Abu Dhabi, the only city in our chart where rents fell, dropped nine places as its three-year housing slump continued.

