Singapore and São Paulo now in Top10 of world's most expensive cities. For the second year in a row, Luanda, in Angola, is the most expensive city in the world for employees posted abroad, according to the most recent cost of living survey carried out in 2011 by Mercer consultants. Tokyo (Japan) remains in second place and N'Djamena (Chad) is still in third place. Moscow is in fourth position, followed by Geneva in fifth and Osaka in sixth place. Zurich has gone up one place and is now in...