What Are Asset Price Bubbles? A Survey on Definitions of Financial Bubbles
系统梳理了122篇来自11个研究领域的论文，归纳出资产价格泡沫的多种定义，发现最常用的是偏离预期未来现金流现值，但也存在其他基于价格特征或基本面价值的定义。
ABSTRACT Financial bubbles and crashes have repeatedly caused economic turmoil notably but not just during the 2008 financial crisis. However, both in the popular press as well as scientific publications, the meaning of bubble is sometimes unspecified. Due to the multitude of bubble definitions, we conduct a systematic review with the following questions: What definitions of asset price bubbles exist in the literature? Which definitions are used in which disciplines and how frequently? We develop a system of definition categories and categorize a total of 122 papers from 11 research areas. Our results show that although one definition is indeed prevalent in the literature, the overall definition landscape is not uniform. Next to the mostly used definition as deviation from a present value of expected future cash flows, we identify several other definitions, which rely on price properties or other specifications of a fundamental value. This research contributes by shedding light on the possible variations in which bubbles are defined and operationalized.