According to the IMF's survey of 51 OECD countries, only houses in New Zealand and Canada are selling at a greater divergence from their historic price-to-rent ratio, while houses in Norway were the seventh most expensive in comparison to average incomes. 

 

In a blog post on Thursday, IMF Deputy Managing Director Min Zhu  called for country's to take action to contain house prices or risk a future financial crisis. 

 

"Our research indicates that boom-bust patterns in house prices preceded more than two-thirds of the recent 50 systemic banking crises," he wrote. 

 

Here's a chart comparing Norway's deviation from historic price-to-rent ratios: 

 

 

 

And here's once comparing the relationship between house prices and average incomes: