The Persistence of Bias: Algorithms Inherit Behavioral Biases in Earnings Forecasts
with Murray Frank, and Keer Yang
CICF 2025, Financial Intermediation in the 3rd Millennium (2025), JFDS Conference 2023, Cardiff Fintech Conference 2023, FMA 2023, HKUST, UC Davis Finance Day, and University of Minnesota ,
Machine learning algorithms are known to outperform human analysts in predicting corporate earnings, leading to their rapid adoption. However, we show that leading methods (gradient boosting, neural nets, ChatGPT) systematically exhibit over- and under-reaction biases similar to human forecasts. The behavioral bias is primarily due to biases in the training data and we show that it cannot be eliminated without compromising accuracy. Analysts with machine learning training overreact much less than do traditional analysts. Our findings suggest that AI tools reduce but do not eliminate behavioral biases in financial markets. We provide a model showing that there is a tradeoff between predictive power and rational behavior.