Economics A-Z | Economist.com

Economics A-Z | Economist.com: "Bubble When the price of an asset rises far higher than can be explained by fundamentals, such as the income likely to derive from holding the asset. The Chicago Tribune of April 13th 1890, writing about the then mania in real-estate prices, described 'men who bought property at prices they knew perfectly well were fictitious, but who were prepared to pay such prices simply because they knew that some still greater fool could be depended on to take the property off their hands and leave them with a profit'. Such behaviour is a feature of all bubbles. Famous bubbles include tulip mania in Holland during the 17th century, when the prices of tulip bulbs reached unheard of levels, and the South Sea Bubble in Britain a century later, although there have been many others since, including the dotcom bubble in internet company shares that burst in 2000. Economists argue about whether bubbles are the result of irrational crowd behaviour (perhaps coupled with exploitation of the gullible masses by some savvy speculators) or, instead, are the result of rational decisions by people who have only limited information about the fundamental value of an asset and thus for whom it may be quite sensible to assume the market price is sound. Whatever their cause, bubbles do not last forever and often end not with a pop but with a crash."