Volume 1, Number 1, 2000 Abstracts
© Copyright Erlbaum 2000

Thought Contagions in the Stock Market
Aaron Lynch

The evolutionary epidemiology of ideas, or thought contagion theory, is introduced and applied to possible examples in the stock market. It is suggested that differences in transmissivity, receptivity, and longevity of belief may contribute numerous irrational influences on the stock market, generating sources of inefficiency. These include a wide variety of mechanisms that may generate both positive and negative market overreactions. The soaring prices of Internet stocks during 1998-1999 are used as an example of how investment ideas correlating with new communication behaviors may affect share prices, and how contagion effects in general can affect the broader market. New avenues of empirical investigation are proposed to test the types of hypotheses presented.

Overreactions, Momentum, Liquidity, and Price Bubbles in Laboratory and Field Stock Markets
Gunduz Caginalp
David Porter
Vernon Smith

Laboratory asset markets provide an experimental setting in which to observe investor behavior. Over more than a decade, numerous studies have found that participants in laboratory experiments frequently drive asset prices far above fundamental value, after which the prices crash. This bubble-and-crash behavior is robust to variations in a number of variables, including liquidity (the amount of cash available relative to the value of the assets being traded), short-selling, certainty or uncertainty of dividend payments, brokerage fees, capital gains taxes, buying on margin, and others. This paper attempts to model the behavior of asset prices in experimental settings by proposing a "momentum model" of asset price changes. The model assumes that investors follow a combination of two factors when setting prices: fundamental value, and the recent price trend. The predictions of the model, while still far from perfect, are superior to those of a rational expectations model, in which traders consider only fundamental value. In particular, the momentum model predicts that higher levels of liquidity lead to larger price bubbles, a result that is confirmed in the experiments. The similarity between laboratory results and data from field (real-world) markets suggests that the momentum model may be applicable there as well.

Measuring Bubble Expectations and Investor Confidence
Robert J. Shiller

This paper presents evidence on two types of investor attitudes that change in important ways through time, with important consequences for speculative markets. The paper explores changes in bubble expectations and investor confidence among institutional investors in the U.S. stock market at six-month intervals for the period 1989 to 1998 and for individual investors at the start and end of this period.

Based on the results of the questionnaires administered during the period, the author develops specific time-series indicators for each of the following: a speculative bubble (an unstable situation with expectations for a increase in the short term only), a negative speculative bubble (an unstable situation with expectations for a downturn in the short term only), and investor confidence (a feeling that nothing can go wrong).

Using the indicators, the author produces indexes indicating the average percentage of the population at a given time with bubble expectations, negative bubble expectations, and investor confidence, respectively.

Investor Overreaction: Evidence That Its Basis Is Psychological
David N. Dreman
Eric A. Lufkin

Probably no subject in recent financial literature has generated more controversy than whether investors behave rationally in pricing stocks, or whether they overreact to market information, resulting in prices being too high or too low. Although the efficient market hypothesis states that, with minor exceptions, securities are rationally priced, repeated evidence has been presented of predictable over- and underreactions. This evidence is based primarily on consistently higher returns for out-of-favor stocks and below-average returns for favored issues. The existence of overreaction in the marketplace, if it can be proven, is important to both investment decision-making and theory, and in more acute cases can be the major cause of financial bubbles and panics.

We present evidence of overreaction by showing that important fundamentals upon which securities prices depend demonstrate little movement in the face of major changes to the returns of favored and unfavored stocks. We can find no explanation other than psychological influences to account for this finding. The paper also provides evidence that over- and underreaction may be a part of the same process.

A Cat Bond Premium Puzzle?
Vivek J. Bantwal
Howard C. Kunreuther

Catastrophe bonds, the payouts of which are tied to the occurrence of natural disasters, offer insurers and corporate entities the ability to hedge events that could otherwise impair their operations to the point of insolvency. At the same time, cat bonds offer investors a unique opportunity to enhance their portfolios with an asset that provides a high-yielding return that is uncorrelated with the market. Despite the attractive nature of these investments, spreads in this market remain considerably higher than the spreads for comparable speculative-grade debt. This article uses behavioral economics to explain the reluctance of investment managers to invest in these products. Finally, we use simulations to illustrate the attractiveness of cat bonds under a wide range of outcomes, including the possible effects of model uncertainty on investor appetite for these securities.

When Cultures Collide: Social Security and the Market
William M. O'Barr
John M. Conley

In his 1999 State of the Union address, President Clinton raised the possibility of investing social security funds in the equities market. In this article, two anthropologists who have studied the culture of the financial world assess the President's proposal. The analysis focuses on the vast cultural gap between the private-sector participants in the equities market and the federal bureaucrats who would inevitably manage social security investments. The authors examine similar arrangements at the state level, the cultural differences among the entities involved, and how those differences interfere with fiduciary decision-making. They conclude that the gap is simply too wide for the proposal to be workable, and as a result, the adverse consequences likely outweigh the potential benefits. Although some consequences are foreseeable, more threatening consequences can be envisioned only in the most general terms.