Ensemble Forecasting: A Better Default for Business Forecasting

Why no single model is uniformly best across a portfolio of heterogeneous series, and how combination delivers the accuracy of the best available model without requiring you to identify it.

ensemble forecasting

Three Approaches to Model Selection

Every portfolio forecast resolves the same decision: which model issues the number. The three available approaches differ in one respect only, which is how much evidence stands behind that decision.

Per-Series Selection

Choose the winning model for each series from its own validation window. Across 293 out-of-sample backtests it identified the eventual best model 26% of the time, and combination beat it in 200 of them.

Portfolio-Level Selection

Rank the models on pooled validation evidence and apply the winner across every series. It reaches parity with combination, but only once roughly 150 backtests have accumulated, which is around 50 qualifying series.

Model Combination

Average the member forecasts each period with the extremes trimmed. It matches the best available single model from the first backtest and lands in the bottom three of eleven methods in 1% of backtests against 17.4%.

Discover more White Papers

  • Outer Cover - State Of Unified

    White Papers

    The State of Unified Marketing Measurement 2026

    Winterberry Group & Lifesight The State of Unified Marketing Measurement 2026 Winterberry Group surveyed...

    Download now
  • The State of Footwear & Apparel Marketing for 2027 outer

    White Papers

    Running the Numbers

    Stop optimizing for cheap first orders. Discover how to measure the marketing that creates long-term customer routines.

    Download now
  • Outer Cover - Who Actually?Caused the Booking

    White Papers

    Who Actually Caused the Booking?

    Grow revenue without torching contribution margin. Know exactly what to scale, what to cut, and where the next dollar stops paying.

    Download now

You may also like

  • RTB House X Lifesight

    Published on: October 6, 2026

    Measure the Incremental Impact of Your RTB House Campaigns

    Connect RTB House to Lifesight to see the incremental revenue your campaigns drive and plan budgets on incremental return, not platform-reported ROAS.

    Read blog
  • Did it Work Cover

    Published on: October 6, 2026

    “Did it work?” The 100-year-old question marketing still can’t answer

    We measure everything, but know less than ever. Here's why the 'Holy Grail' of attribution remains out of reach, and what to do about it.

    Read blog
  • top MMM providers 2027

    Published on: October 1, 2026

    10 Best Marketing Mix Modeling Providers in 2027 (Compared)

    Compare the best MMM providers in 2027, including top marketing mix modeling companies, key features, methodologies, and use cases.

    Read blog