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The impact of covariance misspecification in risk-based portfolios
The equal-risk-contribution, inverse-volatility weighted, maximum-diversification and minimum-variance portfolio weights are all direct functions of the estimated covariance matrix. We perform a Monte Carlo study to assess the impact of covariance matrix misspecification to these risk-based portfolios at the daily, weekly and monthly forecasting horizon. Our results show that the equal-risk-contribution and inverse-volatility weighted portfolio weights are relatively robust to covariance misspecification. In contrast, the minimum-variance portfolio weights are highly sensitive to errors in both the estimated variances and correlations, while errors in the estimated correlations can have a large effect on the weights of the maximum-diversification portfolio.
On the properties of financial analyst earnings forecasts: some new evidence
The importance of information in the formation process of security prices has a long history. The dissemination of information can take on different forms depending on the legal constraints. However, in all developed financial markets, financial analysts play a prominent role in collecting, analysing and diffusing information. Financial analysts typically supply future earnings estimates and stock picking advices in the form of recommendations. Earnings estimates are the essential part of security valuation by analysts and investors. They have even become an integral part of financial reporting in the financial press. Early research has accumulated evidence that these estimates are optimistically biased. More recently, empirical studies have found that analysts' optimistic bias is lessening, that its extent differs across analysts, firm characteristics and countries. Broadly speaking, this dissertation investigates the determinants of financial analyst forecasts bias. In the first essay, I examine the relative accuracy of European financial analysts' earnings forecasts and its determinants. I show that the results obtained for US analysts can not be generalised to European analysts who face a seemingly different job market as well as several different institutional and economic environments. In the second essay, I investigate the influence of financial analysts' location on their performance. More precisely, I examine the relative performance of local versus foreign analysts on Latin American stock markets. I find foreign analysts to be more timely and more accurate than their local counterparts. In addition, I document stronger price reactions after foreign analysts' forecast revisions than after those of local analysts. The third essay is related to the declining pattern of financial analyst forecast bias. In particular, I investigate whether US CEOs compensation arrangements give CEOs incentives to manipulate analysts' expectations downward in order to release earnings that meet or beat market estimates. The results confirm this hypothesis. I document a strong link between expectations management and the relevant option component of CEO compensation, bonus plans, and the percentage of the company's shares owned by the CEO who manages it.