Marc Oliver Rieger

Risk Preferences Around the World

We present results from a large-scale international survey on risk preferences conducted in 53 countries. In all countries, we find, on average, an attitude of risk aversion in gains and of risk seeking in losses. The degree of risk aversion shows significant cross-country differences. Moreover, risk attitudes in our sample depend not only on economic conditions but also on cultural factors, as measured by the Hofstede dimensions individualism and uncertainty avoidance. The data may also serve as an interesting starting point for further research on cultural differences in behavioral economics. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1869 . This paper was accepted by Peter Wakker, decision analysis.

What is behind the priority heuristic? A mathematical analysis and comment on Brandstätter, Gigerenzer, and Hertwig (2006).

Comments on the article by E. Brandstätter, G. Gigerenzer, and R. Hertwig. The authors discuss the priority heuristic, a recent model for decisions under risk. They reanalyze the experimental validity of this approach and discuss how these results compare with cumulative prospect theory, the currently most established model in behavioral economics. They also discuss how general models for decisions under risk based on a heuristic approach can be understood mathematically to gain some insight in their limitations. They finally consider whether the priority heuristic model can lead to some understanding of the decision process of individuals or whether it is better seen as an as-if model.

Prospect Theory Around the World

We present results from the first large-scale international survey on risk preferences, conducted in 45 countries. We show substantial cross-country differences in risk aversion, loss aversion and probability weighting. Moreover, risk attitudes in our sample depend not only on economic conditions, but also on cultural factors, as measured by the Hofstede dimensions Individuality and Uncertainty Avoidance. The presented data might also serve as an interesting starting point for further research in cultural economics.

Can utility optimization explain the demand for structured investment products

In this paper, we first show that for classical rational investors with correct beliefs and constant absolute or constant relative risk aversion, the utility gains from structured products over and above a portfolio consisting of the risk-free asset and the market portfolio are typically much smaller than their fees. This result holds irrespectively of whether the investors can continuously trade the risk-free asset and the market portfolio at no costs or whether they can just buy the assets and hold them to maturity of the structured product. However, when considering behavioural utility functions, such as prospect theory, or investors with incorrect beliefs (arising from probability weighting or probability misestimation), the utility gain can be sizable.

Young Measure Solutions for Nonconvex Elastodynamics

We study the nonlinear equation of elastodynamics where the free energy functional is allowed to be nonconvex. We define the notion of Young measure solutions for this problem and prove an existence theorem in this class. This can be used as a model for the evolution of microstructures in crystals. We furthermore introduce an optional coupling with a parabolic equation and prove the existence of a Young measure solution for this system.

Why Do Investors Buy Bad Financial Products? Probability Misestimation and Preferences in Financial Investment Decision

We study the influence of systematic probability misestimation on complex financial investment decisions on the context of structured financial products. Structured products have become more and more complex. We study the question whether this complexity might be a sophisticated method to exploit systematic biases in probability estimation of investors in order to make products look safer and more attractive than they actually are. We present results of an experiment that focused on probability estimates in the context of certain classes of structured products, in particular barrier reverse convertibles, bonus certificates, and worst-of basket certificates. We find that behavioral biases, for example, the conjunction fallacy, increase the subjective attractiveness of these product types. We also investigate potential ways to de-bias investors by providing additional information.

Explaining Asymmetric Volatility around the World

Based on the APARCH model and two outlier detection methods, we compute reliable time series of volatility asymmetry for 49 countries with relatively few observations. Results show a steady increase in the asymmetry over the years for most countries. We find that economic development and market capitalization/GDP are the most important factors that increase volatility asymmetry. We also find that higher participation of private investors and coverage by financial analysts increase the asymmetry, suggesting investor sentiment as a driving force. Leverage and feasibility of short selling increase volatility in falling market conditions, although only to a smaller extent.

Co-monotonicity of optimal investments and the design of structured financial products

We prove that, under very weak conditions, optimal financial products on complete markets are co-monotone with the reversed state price density. Optimality is meant in the sense of the maximization of an arbitrary preference model, e.g., expected utility theory or prospect theory. The proof is based on a result from transport theory. We apply the general result to specific situations, in particular the case of a market described by the Capital Asset Pricing Model or the Black–Scholes model, where we derive a generalization of the two-fund-separation theorem and give an extension to APT factor models and structured products with several underlyings. We use our results to derive a new approach to optimization in wealth management, based on a direct optimization of the return distribution of the portfolio. In particular, we show that optimal products can (essentially) be written as monotonic functions of the market return. We provide existence and nonexistence results for optimal products in this framework. Finally we apply our results to the study of bonus certificates, show that they are not optimal, and construct a cheaper product yielding the same return distribution.

Financial Market Equilibria with Cumulative Prospect Theory

The paper shows that financial market equilibria need not exist if agents possess cumulative prospect theory preferences with piecewise-power value functions. The reason is an infinite short-selling problem. But even when a short-sell constraint is added, non-existence can occur due to discontinuities in agents demand functions. Existence of equilibria is established when short-sales constraints are imposed and there is also a continuum of agents in the market.

Too Risk-Averse for Prospect Theory?

We observe that the standard variant of Prospect Theory cannot describe very risk-averse choices in simple lotteries. This makes it difficult to accommodate it with experimental data. Using an exponential value function can solve this problem and allows to cover the whole spectrum of risk-averse behavior. Further evidence in favor of the exponential value function comes from the evaluation of data from a large scale survey on preferences over lotteries where the exponential value function produces the best fits. The results enhance the understanding on what types of lotteries pose potential problems for the classical value function.