Robust monitoring machine:a machine learning solution for out‑of‑sample R_(2)‑hacking in return predictability monitoring  

作　　者：James Yae Yang Luo 

机构地区：[1]C.T.Bauer College of Business,University of Houston,4750 Calhoun Rd,Houston,TX 77204,USA

出　　处：《Financial Innovation》2023年第1期2701-2728,共28页金融创新（英文）

摘　　要：The out-of-sample R^(2) 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 sample.Using ensemble machine learning techniques,we create a virtual environment that prevents researchers from peeking into the intuition in advance when performing out-of-sample prediction simulations.We apply this approach to robust monitoring,exploiting a dynamic shrink-age effect by switching between a proposed forecast and a benchmark.Considering stock return forecasting as an example,we show that the resulting robust monitoring forecast improves the average performance of the proposed forecast by 15%(in terms of mean-squared-error)and reduces the variance of its relative performance by 46%while avoiding the out-of-sample R^(2)-hacking problem.Our approach,as a final touch,can further enhance the performance and stability of forecasts from any models and methods.

关 键 词：Machine learning Out-of-sample R^(2)-hacking Return predictability MONITORING 

分 类 号：C52[社会学] C53[文化科学] C55C58G17