This article reviews the theory of speculative bubbles. Bubbles are a promising candidate as an explanation for the stock price run-up and collapse of the 1990s in the United States. The theory considers both irrational and rational bubbles, with emphasis on the latter. Rational bubbles, defined...

By 'the paradox of asset pricing' Peter Bossaerts refers to his contention that, despite its apparent generality and sophistication, the theory of finance has largely been a failure empirically. Bossaerts reviews the major areas of finance: theory, empirical methods, empirical results and...

markets, as well as predictions for optimal default by borrowers.

Recent years have seen a protracted debate on the "fiscal theory of the price level". This doctrine is based on the intertemporal government budget constraint, which says that the real value of the government debt equals the discounted value of future government surpluses. It is observed that...

The single most important proposition in economic theory, first stated by Adam Smith, is that competitive markets do a good job allocating resources. Vilfredo Pareto’s later formulation was more precise than Smith’s, and also highlighted the dependence of Smith’s proposition on assumptions...

Bubbles, such as money, cannot be valued in efficient equilibria in overlapping generations models (a borderline case aside). Analysts frequently attribute this result to the fact that if bubbles were valued, the bubble must eventually exceed the endowment of the young. This implies negative...

Mortgage lenders impose a default premium on the loans they originate to compensate for the possibility that borrowers won’t make payments. The housing boom of the 2000s was characterized by increasing riskiness of the borrowers approved for mortgages and the structures of the loans...

House prices have fallen approximately 30% from their peak in 2006, accompanied by a level of defaults and foreclosures without precedent in the post-World War II era. Many homeowners have mortgages with principal amounts higher than the market value of their properties. In general, though, the...