SYDNEY — For most economists, losing a public bet about the direction of the economy might result in a wounded ego. For Steve Keen, it also carried a physical price.

On Thursday, Mr. Keen was to start hiking 225 kilometers, or 140 miles, from Australia’s capital to the top of its highest peak, Mount Kosciuszko, after losing a wager with a rival economist about the future of home prices here.

In November 2008, at the height of the global financial crisis, Mr. Keen, an associate professor of economics and finance at the University of Western Sydney, predicted that prices would plunge by 40 percent from record highs earlier that year.

Australia has one of the world’s highest rates of household debt, and Mr. Keen argued that the country would soon follow the United States and Britain into a downward spiral of defaults and foreclosures. But even as he was making his dire forecast, housing prices were starting to turn around.