Beyond Seasonality: Integrating External Events in Time Series Analysis
In today's data-driven business environment, understanding the patterns in your time series data is essential for making informed decisions. While seasonal decomposition techniques like STL (Seasonal-Trend-Loess) are powerful tools for separating seasonal patterns from underlying trends, they often miss a critical factor: the impact of external events. When analyzing sales, web traffic, or consumer behavior, external events like holidays, promotions, or cultural celebrations can cause significant spikes that traditional time series analysis might misattribute to noise or seasonality. This is particularly true in markets with strong cultural events that dramatically affect consumer behavior. In this article, I'll share a comprehensive approach that extends STL decomposition to: 1. Normalize for price impacts using elasticity models 2. Account for external events using your own events calendar 3. Handle additional factors like promotions and out-of-stock situations 4. Automatical...