For the first time in 16 years, U.S. house prices have fallen, raising fears over the economy. This could in turn have a knock-on effect on the rest of the world.

This doesn’t seem to be an isolated incident, as the UK Land Registry is reporting a long-expected fall in the British property market — a 1.1 percentage fall last month, bolstered only by buoyant figures for London.

Standard & Poor’s/Case Shiller Index reports that American values fell 1.4 percent in the first quarter compared with the same period last year. They were also down 0.7 percent on the final quarter of 2006.

The OECD (Organization for Economic Cooperation and Development) warned that the spillover effect could be “more pronounced than generally expected”.