The 10 most expensive cities in the world

Expats beware, Hong Kong, Sydney and Vancouver are the most expensive cities in the world to find a home, according to the 13th Annual Demographia International Housing Affordability Study Survey 2017.

Hong Kong, China, has the least affordable housing market for the seventh year in a row. Its median multiple this time was 18.1, down from 19, the worst ranking on record, last year. Sydney, Australia, has a median multiple of 12.2. In Vancouver in the Canadian province of British Columbia house prices rose the equivalent of a full year's household income in only a year; it had a median multiple of 11.8.

The data shows that the most "severely unaffordable major housing markets" are in Australia, New Zealand, China, Canada, the UK, and the US.

Oliver Hartwich, the executive director of the think tank behind the research, The New Zealand Initiative, said: "The number of severely unaffordable major housing markets rose from 26 to 29. High house prices are not a sign of city's success but a sign of failure to deliver the housing that its citizens need."

The study analysed 406 metropolitan housing markets in nine countries – Australia , Canada, Hong Kong, Ireland, Japan, New Zealand, Singapore, and the UK – in the third quarter of 2016, using the "mean multiple" approach – the median house price divided by the median household income.