Thorsten Hens

Does prospect theory explain the disposition effect

The disposition effect is the observation that investors tend to realize gains more than losses. This behavior is puzzling because it cannot be explained by traditional finance theories. A standard explanation of the disposition effect refers to prospect theory and, in particular, to the asymmetric risk aversion, according to which investors are risk-averse when faced with gains and risk-seeking when faced with losses. We show that for reasonable parameter values, the disposition effect cannot, however, be explained by prospect theory. The reason is that those investors who sell winning stocks and hold losing assets would not have invested in stocks in the first place. That is, the standard prospect theory argument is sound ex-post, assuming that the investment occurred, but not ex-ante, requiring also that the investment has to be made in the first place.

The Transfer Paradox and Sunspot Equilibria

We show that for broad classes of economies the existence of sunspot equilibria is equivalent to the occurrence of the transfer paradox. As an application of this equivalence, we demonstrate that in exchange economies without first period consumption, sunspot equilibria cannot exist if there is no potential multiplicity of spot market equilibria.

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.

Financial Innovation, Communication and the Theory of the Firm

When markets are incomplete, the competitive equilibria considered so far are not constrained Pareto-efficient, production efficiency breaks down and shareholders no longer agree on the objective function of the firm. We first show by way of an example that these inefficiencies originate in the double role of firms in incomplete markets: providing high market value and providing good hedging opportunities (spanning role). To disentangle these two conflicting roles of the firms decision, we then suggest to let the firm choose a relevant financial policy by issuing securities being collaterized by the production plan. In order to guarantee that the firm does not choose to innovate trivial assets, it is then shown to be crucial that the firms shareholders agree on the same set of beliefs. Therefore we introduce some communication network into the model which allows the shareholders to exchange their views on the firms best policies. In our main result we demonstrate that competitive equilibria with communication of shareholders and a relevant financial policy of the firm are Pareto-efficient, provided there are at least as many firms as there are shareholders.

Two Paradigms and Nobel Prizes in Economics: A Contradiction or Coexistence?

Markowitz and Sharpe won the Nobel Prize in Economics for the development of Mean-Variance (M-V) analysis and the Capital Asset Pricing Model (CAPM). Kahneman won the Nobel Prize in Economics for the development of Prospect Theory. In deriving the CAPM, Sharpe, Lintner and Mossin assume expected utility (EU) maximisation in the face of risk aversion. Kahneman and Tversky suggest Prospect Theory (PT) as an alternative paradigm to EU theory. They show that investors distort probabilities, make decisions based on change of wealth, exhibit loss aversion and maximise the expectation of an S-shaped value function, which contains a risk-seeking segment. Can these two apparently contradictory paradigms coexist? We show in this paper that although CPT (and PT) is in conflict to EUT, and violates some of the CAPMs underlying assumptions, the Security Market Line Theorem (SMLT) of the CAPM is intact in the CPT framework. Therefore, the CAPM is intact also in CPT framework.

Improving Investment Decisions with Simulated Experience

We apply a new and innovative approach to communicating risks associated with financial products that should support investors in making better investment decisions. In our experiments, participants are able to gain “simulated experience” by random sampling of a previously described return distribution. We find that simulated experience considerably improves participants’ understanding of the underlying risk-return profile and prompts them to reconsider their investment decisions and to choose riskier financial products without regretting their higher risk-taking behavior afterwards. This method of experienced-based learning has high potential for being integrated into real-world applications and services.

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.

On the Micro-Foundations of Money: The Capitol Hill Baby-Sitting Co-Op

This paper contributes to the micro-foundation of money in centralized markets with idiosyncratic uncertainty. It shows existence of stationary monetary equilibria and ensures that there is an optimum quantity of money. The rational solution of our model is compared with actual behavior in a laboratory experiment. The experiment gives support to the theoretical approach.

Existence of Sunspot Equilibria and Uniqueness of Spot Market Equilibria: The Case of Intrinsically Complete Markets

We consider economies with additively separable utility functions and give conditions for the two-agents case under which the existence of sunspot equilibria is equivalent to the occurrence of the transfer paradox. This equivalence enables us to show that sunspots cannot matter if the initial economy has a unique spot market equilibrium and there are only two commodities or if the economy has a unique equilibrium for all distributions of endowments induced by asset trade. For more than two agents the equivalence breaks and we give an example for sunspot equilibria even though the economy has a unique equilibrium for all distributions of endowments induced by asset trade.