Value line and I/B/E/S earnings forecasts

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 [J. Acc. Res. 29 (1991) 397] conducted a similar study, but found no evidence that a,aggegation 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 tuning 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. (C) 2004 International Institute of Forecasters. Published by Elsevier B.V All rights reserved.