Home prices will halve over the next few years, says the only forecaster to have predicted both the record sharemarket run to 2007 as well as the subsequent GFC. And that was in 1993.

More recently, he also predicted the property collapse in the US, selling his Florida home at the peak in 2005 and renting ever since.

He's predicting a second big drop in the US and Australia's first, which, in four years, could turn McMansions into ghost houses.

Harry Dent, who runs the US-based forecaster HS Dent Foundation, isn't alone in predicting property prices will collapse.