We evaluate the performance of different models for the covariance structure of stock returns, focusing on their use for optimal portfolio selection. Comparisons are based on forecasts of future covariances as well as the out-of-sample volatility of optimized portfolios from each model. A few...

We examine whether stock prices fully reflect the value of firms' intangible assets, focusing on research and development (R&D). Since intangible assets are not reported on financial statements under current U.S. accounting standards and R&D spending is expensed, the valuation problem may be...

This paper examines executive turnover -- both for management and supervisory boards - - and its relation to firm performance in the largest companies in Germany in the 1980s. The management board turns over slowly -- at a rate of 10% per year -- implying that top executives in Germany have...