The out-of-sample R2 is designed to measure forecasting performance without look-ahead bias. However, researchers can hack this performance metric even without multiple tests by constructing a prediction model using the intuition derived from empirical properties that appear only in the test...

Out-of-sample R2-hacking problems can arise even without multiple testing if a researcher constructs a prediction model using the intuition derived from empirical properties that appear only in the test sample. We provide a machine-learning solution for this problem in the context of robust...

We put forward a model in which analysts are uncertain about a firm's earnings process. Faced with the possibility of using a misspecified model, analysts issue forecasts that are robust to model misspecification. We estimate that this mechanism explains approximately 60% of the autocorrelation...

Out-of-sample tests are subject to look-ahead bias when a forecaster constructs a model using an intuition derived from empirical patterns in the test sample. Even if model parameters are estimated without the test sample, information from it affects a forecaster's model choice. Since such...