The proposition that investors are overconfident about their valuation and trading skills can explain high observed trading volume. With biased self-attribution, the level of investor overconfidence and thus trading volume varies with past returns. We test the trading volume predictions of formal overconfidence models and find that share turnover is positively related to lagged returns for many months. The relationship holds for both market-wide and individual security turnover, which we interpret as evidence of investor overconfidence and the disposition effect, respectively. Security volume is more responsive to market return shocks than to security return shocks, and both relationships are more pronounced in small-cap stocks and in earlier periods where individual investors hold a greater proportion of shares.

We integrate appealing features of Markowitz’s mean-variance portfolio theory (MVT) and Shefrin and Statman’s behavioral portfolio theory (BPT) into a new mental accounting (MA) framework. Features of the MA framework include an MA structure of portfolios, a definition of risk as the probability of failing to reach the threshold level in each mental account, and attitudes toward risk that vary by account. We demonstrate a mathematical equivalence between MVT, MA, and risk management using value at risk (VaR). The aggregate allocation across MA subportfolios is mean-variance efficient with short selling. Short-selling constraints on mental accounts impose very minor reductions in certainty equivalents, only if binding for the aggregate portfolio, offsetting utility losses from errors in specifying risk-aversion coefficients in MVT applications. These generalizations of MVT and BPT via a unified MA framework result in a fruitful connection between investor consumption goals and portfolio production.

Why do levels of corporate social performance (CSP) differ so much across countries? We answer this question in an examination of CSP ratings of more than 2600 companies from 36 countries. We find that firm characteristics explain very little of the variations in CSP ratings. In contrast, variations in country factors such as stages of economic development, culture, and institutions account for a significant proportion of variations in CSP ratings across countries. In particular, we find that CSP ratings are high in countries with high income-per-capita, strong civil liberties and political rights, and cultures oriented toward harmony and autonomy. Furthermore, we find that home country factors explain a smaller portion of the overall variations in CSP for multinationals and cross-listed firms than for non-multinationals and pure domestic firms, respectively.