This paper focuses on egocentric biases in financial decisions. Subjects first design a portfolio, whereby each combination of assets yields the same expected return and variance of returns. (...)

Overall, 72 subjects invest their endowment in four risky assets. Each com-bination of assets yields the same expected return and variance of returns. Illusion of expertise prevails when one prefers nevertheless the self-selected portfolio. After being randomly assigned to groups of four...