Here is an interesting PDF that provides some global perspectives on housing affordability.
"The 2008 4th Edition Demographia International Housing Affordability Survey rates the housing affordability situation of 227 urban markets of the United Kingdom (28 markets), Republic of Ireland (6), Canada (29), the United States of America (129), Australia (28) and New Zealand (7)."
http://www.demographia.com/dhi.pdf
Brian Creed
"The 2008 4th Edition Demographia International Housing Affordability Survey rates the housing affordability situation of 227 urban markets of the United Kingdom (28 markets), Republic of Ireland (6), Canada (29), the United States of America (129), Australia (28) and New Zealand (7)."
http://www.demographia.com/dhi.pdf
Brian Creed