期刊名称：Discussion Paper Series / Universität Heidelberg, Department of Economics
出版年度：2014
出版社：Universität Heidelberg, Department of Economics
摘要：We develop a parsimonious mo del of bubbles based on the assumption of imprecisely known market depth. In a speculative bubble, traders drive the price above its fun- damental value in a dynamic way, driven by rational expectations about future price developments. At a previously unknown date, the bubble will endogenously burst. We provide a general condition for the possibility of bubbles depending on the risk-free rate, uncertainty about market depth, and traders' degree of leverage. This allows us to discuss several policy measures. Bubbles always reduce aggregate welfare. Among others, certain monetary policy rules, minimum leverage ratios, and a correctly im- plemented Tobin tax can prevent their o ccurrence. Implemented incorrectly, however, some of these measures backfire and facilitate bubbles
