Keywords: Robust optimization Mean–variance portfolio theory Ellipsoidal uncertainty Equilibrium price system a b s t r a c t In a financial market composed of n risky assets and a riskless asset, where short sales are allowed and mean–variance investors can be ambiguity averse, i.e., diffident about mean return estimates where confidence is represented using ellipsoidal uncertainty sets, we de...

Recent research documents that institutional or large investors act as antagonists to other investors by showing opposite trading behavior following disclosure of new information. Using an extremely comprehensive official transactions data set from Finland, we set out to explore the interrelation between investor size and behavior. More specifically, we test whether investor size is positively ...

T paper uses a formal model to study how evaluation costs affect competition for resources in strategic factor markets. It finds that relative scarcity may not always benefit resource sellers. Rather, when competition among resource investors passes a certain threshold intensity, miscoordination among investors increases to the point that sellers’ expected profits decline. This paper extends th...

This paper presents a model of portfolio choice and stock trading volume with lossaverse investors. The demand function for risky assets is discontinuous and non-monotonic: as wealth rises beyond a threshold investors follow a generalized portfolio insurance strategy. This behavior is consistent with the evidence in favor of the disposition effect. In addition, loss-averse investors will not ho...

Myopic loss aversion is the combination of a greater sensitivity to losses than to gains and a tendency to evaluate outcomes frequently. Two implications of myopic loss aversion are tested experimentally. 1. Investors who display myopic loss aversion will be more willing to accept risks if they evaluate their investments less often. 2. If all payoffs are increased enough to eliminate losses, in...

We examine whether investing experience can dampen the disposition effect, that is, the fact that investors seem to hold on to their losing stocks to a greater extent than they hold on to their winning stocks. To do so, we devise a computer program that simulates the stock market. We use the program in an experiment with two groups of subjects, namely experienced investors and undergraduate stu...

When capital is sunk after it is invested, a host government facing heterogeneous foreign investors has a strong incentive to reduce preferential taxes over time in order to attract less eager investors while fully expropriating past investors. This induces investors to wait rather than invest in the initial period, and leads to loss of tax revenue. This dynamic inconsistency problem is resolve...

We study how intermediation and asset prices in over-the-counter markets are affected by illiquidity associated with search and bargaining. We compute explicitly the prices at which investors trade with each other, as well as marketmakers’ bid and ask prices, in a dynamic model with strategic agents. Bid–ask spreads are lower if investors can more easily find other investors or have easier acce...

Using data on security holdings of 10,771 institutional investors from 72 different countries, we test whether concentrated investment strategies result in superior abnormal returns to institutional investors. We examine three measures of portfolio concentration: home country, foreign country, and industry concentration and show that portfolio concentration leads to higher abnormal returns of i...

Using an agent-based multi-asset artificial stock market, we simulate the survival dynamics of investors with different risk preferences. It is found that the survivability of investors is closely related to their risk preferences. Among the eight types of investors considered in this paper, only the CRRA investors with RRA coefficients close to one can survive in the long run. Other types of a...