We show that prospect theory is a valuable paradigm for wealth management. It describes well how investors perceive
risk and with appropriate modeling it can be made consistent with rational decision making. Moreover, it can be
represented in a simple reward-risk diagram so that the main ideas are easily communicated to clients. Finally, we
show on data from a large set of private clients that there are considerable monetary gains from introducing prospect
theory instead of mean-variance analysis into the client advisory process.
We develop statistical methods to detect informed trading in options markets. We apply these methods to 31 companies from various sectors over 14 years analyzing approximately 9.6 million option prices. We find that option informed trading tends to cluster prior to certain events, takes place more in put than call options, generates easily large gains exceeding millions,is not contemporaneously reflected in the underlying stock price, involves around the money options during calm times and out-of-the-money options during turbulent times. These findings are not driven by false discoveries in informed trades which are controlled using multiple hypothesis testing techniques.
We review and examine three market-based instruments to address the challenge of climate change: emission trading, emission taxes, and hybrid instruments. Our main contribution is the illustration and comparison of these instruments using recent results from theoretical research and practical policy experience. Hybrid policies that aim to combine taxes and permits emerge as a promising way forward. An additional contribution is that we also comment on two other related concepts, namely, innovation strategies and prediction markets. For the former, we show that, to make economic sense, the much publicized Asia-Pacific Partnership on Clean Development and Climate has to rely on the same basic tool as the other instruments, namely, relative prices. For the latter, we discuss how prediction markets can complement traditional scenario analysis by experts. They are likely to improve the practical implementation of all previously discussed methods.
The article puts forward the view that the regulatory perspective on systemic risk should be changed drastically. The sub-prime crisis has indeed revealed many loopholes in the supervisory/regulatory framework for banks—in particular, the inability to deal with the too-big-to-fail syndrome and also the lack of resiliency of interbank and money markets. To a large extent, the contagion phenomena that took place in these markets were the necessary outcomes of the passive attitude of banking supervisors, who have let large banks develop a complex and opaque nexus of bilateral obligations. We propose two reforms: adopting a platform-based (instead of institutionbased) regulatory perspective on systemic risk and encouraging a generalized move to central counterparty clearing.
Multiplicity of equilibria is a prevalent problem in many economic models. Often equilibria are characterized as solutions to a system of polynomial equations. This paper gives an introduction to the application of GrÄobner basis methods for ¯nding all solutions of a polynomial system. The Shape Lemma, a key result from algebraic geometry, states under mild assumptions that a given equilibrium system has the same solution set as a much simpler triangular system. Essentially the computation of all solutions then reduces to ¯nding all roots of a single polynomial in a single unknown. The software package Singular computes the equivalent simple system. If all coeficients in the original equilibrium equations are rational numbers or parameters then the GrÄobner basis computations of Singular are exact. This fact implies that the GrÄobner basis methods cannot only be used for a numerical approximation of equilibria but in fact may allow the proof of theoretical results for the underlying economic model.
Three economic applications illustrate that without much prior knowledge of algebraic geometry GrÄobner basis methods can be easily applied to gain interesting insights into many modern economic models.
This article is concerned with gradient flows in asymmetric metric spaces, that is, spaces with a topology induced by an asymmetric metric. Such an asymmetry appears naturally in many applications, e.g., in mathematical models for materials with hysteresis. A framework of asymmetric gradient flows is established under the assumption that the metric is weakly lower-semicontinuous in the second argument (and not necessarily on the first), and an existence theorem for gradient flows defined on an asymmetric metric space is given.
