“The basic intuition is straightforward. If the reason that the price is high today is only because investors believe he selling price will be high tomorrow, when ”fundamental” factors do not seem to justify such a price, then a bubble exits.”

Joseph E. Stiglitz (1990), “Symposium on bubbles”, Journal of Economic Perspectives, Vol. 4 No.2  Stiglitz vant Nobelprisen i økonomi i 2001.

“There is a bubble if the (real) price of an asset first increases dramatically over a period of several months or years and then almost immediately falls dramatically.”

Hans Lind (2009), “Price bubbles in housing markets”, International Journal of Housing Markets an Analysis, Vol. 2, No. 1 Hans Lind er professor ved KTH i Stockholm og en anerkjent boligøkonomi, som blant annet ledet The European Real Estate Society Conferance 2009.