The principles underpinning Dent’s predictions are sound, and his concerns are shared by many economists globally. That is, that Australia and the world's insatiable appetite for debt, is getting out of control. At some point there will be a dramatic halt, and when that point hits, get ready for GFC Mark II. Where Dent gets people offside – some economic commentators have taken issue with what they regard as outlandish forecasts – is the extent of how harsh impending economic crashes will be. Take for example Dent's latest prediction for Australia: he suggests there will be a 40 to 50 per cent dive in real estate prices that will send the nation into a recession. (Less bearish economists in Australia suggest that if there is a house price correction, it is more likely in the 10 to 20 per cent range). House price growth around Australia is expected to ease but who will make the most accurate call? Credit:Nick Moir

He says while Australia escaped a recession in 2008-09, “this time it is going to get hit in real estate and exports to China". "Your stocks will go down," Dent tells Fairfax Media ahead of a planned visit to Australia later this month. "It’s going to be the sale of a lifetime.” Given Dent and his firm make money from encouraging people to invest and grow their wealth, he isn’t telling investors to simply save and pay down their debt. Rather, he wants them to “take their gains and invest them in safe assets”, albeit with lower returns, such as Treasury bonds in the US, and government bonds in Australia. “Take your gains and put them in safe place so when this global crash does occur, you can buy real estate at an unbelievable bargain,” he says.

His wait-to-buy theory also applies to bitcoin and other cryptocurrencies. Again, he warns investors to stay away – for now. “I’m sitting here in Puerto Rico where a lot of cryptocurrencies are moving for tax advantages,” he says. Harry Dent now resides in Puerto Rico, which was recently hit by hurricanes. Credit:AP Bitcoin, he says, isn’t big enough to chill the economies around the world, but it’s the pin that could cause the bubble to pop. Dent believes in the future of blockchain technologies that make financial transactions more efficient, but predicts the winners will be the cryptocurrency equivalents of Amazon that survived and grew despite the dot-com bust.

He suggests Ripple may be one that outlives the impending crash. "Ripple is about people in the US, immigrants, transferring money much more cheaply to relatives in Mexico," he says. "That's a real business." But companies just raising money cheaply from unsophisticated investors through ICOs – those that "just throw something on the net and say, 'we have bitcoin offering, buy it'. This is terrible ... it will burst badly". "If you buy these stocks when bitcoin is at $15,000 or $20,000 you’re going to get your ass handed to you," he says. Harry Dent: "If you buy these stocks when bitcoin is at $15,000 or $20,000 you’re going to get your ass handed to you". Credit:Chris Ratcliffe

When it comes to the future of the world economy, Dent is even more worried. Central banks worldwide have been printing money to offset what should have been a natural correction to over-leveraging, he says. Global debt – total debt incurred by the household, government, financial and non-financial corporate sectors -rose to a record $233 trillion in the third quarter of 2017, more than $16 trillion higher from end-2016, according to an analysis by the Institute of International Finance. The IIF report also noted record highs for private non-financial sector debt in Canada, France, Hong Kong, Korea, Switzerland, and Turkey, and warned that as a result of this huge debt burden central banks may be reluctant to tighten lending. “This bubble has gone on longer than you could imagine with artificial stimulus, with quantitative easing and now tax cuts,” Dent says. “It will probably burst in the first part of 2018.”

The world is in an economic bubble: Harry Dent. Credit:Judy Green He is especially worried for America. While US President Donald Trump is putting himself forward as an economic messiah, saying his tax cuts and infrastructure spending will stimulate jobs and growth, Dent says the tax cuts are just “free money” and any positive impact will be short-lived. Dent's well-known spending wave theory is that consumer spending is dependent on generational trends and that these trends in turn impact the market value of investments and wider economy. He says spending increases as people age and have children. It peaks at 48, and then slows in down as people approach retirement and work less.

Trump's tax cuts and infrastructure spend, therefore, becomes irrelevant Dent says, since decreased spending by the current generation of US baby boomers will still cause a downturn. US President Donald Trump claims his tax cuts and infrastructure spend will help propel the US economy Credit:AP He also says China is “so over-leveraged and so over-invested” that its economy will crash, worsening Australia’s downturn due to real estate price falls. The silver lining for Australia – and it’s one of few countries in the world that have one according to Dent – is that its underlying demographics are sound. Australia’s population is growing, propelled by “calculated immigration”, and the nation will continue making goods and services to service a growing market in Asia.