Article ID: | iaor20052918 |
Country: | Netherlands |
Volume: | 21 |
Issue: | 1 |
Start Page Number: | 185 |
End Page Number: | 198 |
Publication Date: | Jan 2005 |
Journal: | International Journal of Forecasting |
Authors: | Shane Philip, Ramnath Sundaresh, Rock Steve |
Keywords: | forecasting: applications |
This paper compares Value Line and Institutional Brokers Estimate System (I/B/E/S) analysts' earnings forecasts. Comparing the accuracy of forecasts of a single forecaster (Value Line) to consensus forecasts (I/B/E/S) offers a powerful test of the aggregation principle. Philbrick and Ricks conducted a similar study, but found no evidence that aggregation matters. Using more recent data, we reach different conclusions, finding that I/B/E/S earnings forecasts outperform Value Line significantly in terms of accuracy and as proxies for market expectations. I/B/E/S forecasting superiority is largely explained by its timing advantage and the aggregation principle. However, when we build an I/B/E/S consensus using forecasts from the I/B/E/S detail files of individual analyst forecasts, we find that some of its forecasting superiority remains after controlling for these advantages.