Machine Learning vs Statistical Methods for Time Series Forecasting: Size Matters
This addresses a key debate in forecasting research, clarifying conditions for method effectiveness, but is incremental as it builds on prior comparisons.
The paper tackles the claim that machine learning methods underperform statistical methods in time series forecasting by showing this only holds at low sample sizes, and demonstrates that machine learning improves relative performance as sample size increases.
Time series forecasting is one of the most active research topics. Machine learning methods have been increasingly adopted to solve these predictive tasks. However, in a recent work, these were shown to systematically present a lower predictive performance relative to simple statistical methods. In this work, we counter these results. We show that these are only valid under an extremely low sample size. Using a learning curve method, our results suggest that machine learning methods improve their relative predictive performance as the sample size grows. The code to reproduce the experiments is available at https://github.com/vcerqueira/MLforForecasting.