Tulip mania (Dutch: tulpenmanie) was a period in the Dutch Golden Age during which contract prices for some bulbs of the recently introduced and fashionable tulip reached extraordinarily high levels and then dramatically collapsed in February 1637. It is generally considered the first recorded speculative bubble; although some researchers have noted that the Kipper und Wipper (literally "Tipper and See-Saw") episode in 1619–1622, a Europe-wide chain of debasement of the metal content of coins to fund warfare, featured mania-like similarities to a bubble. In many ways, the tulip mania was more of a hitherto unknown socio-economic phenomenon than a significant economic crisis. Historically, it had no critical influence on the prosperity of the Dutch Republic, the world's leading economic and financial power in the 17th century. Also, from about 1600 to 1720 the Dutch had the highest per capita income in the world. The term "tulip mania" is now often used metaphorically to refer to any large economic bubble when asset prices deviate from intrinsic values.