Forecasting

ML & Bayesian Forecasting Services

When relationships are non-linear, predictors are many, or uncertainty must be quantified rigorously, machine-learning and Bayesian methods extend what classical forecasting can do. MAS Research builds ML, deep-learning, and Bayesian forecasts—and hybrid econometric-ML models—benchmarked honestly against simple methods, because sophistication only counts if it forecasts better.

Machine-learning and Bayesian forecasting use flexible or probabilistic models to predict time series. ML and deep-learning methods (gradient boosting, LSTMs, and related architectures) capture non-linearities and many predictors; Bayesian forecasting produces full predictive distributions with coherent uncertainty; and hybrid econometric-ML models combine the two. All must be validated out of sample against simple benchmarks, which they do not always beat.

ML & deep-learning forecasting Bayesian predictive distributions Hybrid econometric-ML Benchmarked out of sample
A probabilistic forecast distribution History followed by a forecast shown as nested probability bands and sample paths, representing the full predictive distribution. bayesian_forecast · the whole distribution value time observed predictive distribution credible bands sample paths
Predictive distribution history forecast

What ML and Bayesian forecasting add

Classical time-series methods are strong, often hard-to-beat baselines—but they assume largely linear structure and struggle when relationships are non-linear, when there are many potential predictors, or when uncertainty needs to be represented richly. Machine-learning and Bayesian approaches extend the toolkit for exactly these situations, each bringing a distinct strength.

Machine-learning forecasting uses flexible algorithms—gradient boosting, random forests, and related models with engineered time-series features (lags, rolling statistics, calendar effects)—to capture non-linearities and interactions, and to exploit many predictors at once. Deep-learning forecasting goes further for complex, high-volume, or multi-series problems, using architectures built for sequences (LSTMs, and modern transformer-based forecasters) that can learn long-range patterns and forecast many related series together. Bayesian forecasting takes a different angle: rather than a single point forecast, it produces a full predictive distribution, propagating parameter and model uncertainty into coherent intervals—and it handles structural time-series components (trend, seasonality, holidays) and the incorporation of prior knowledge elegantly. And hybrid econometric-ML models combine an interpretable econometric backbone with ML’s flexibility, aiming for both insight and accuracy.

When to use which—and a necessary caveat

Use ML forecasting when non-linearities and many predictors are central and you have enough data to fit and validate a flexible model. Use deep learning for large-scale, high-frequency, or many-series problems where its capacity pays off—it is data-hungry and rarely worthwhile on short series. Use Bayesian forecasting when rigorous, decomposable uncertainty matters, when you want to encode prior information, or when a structural, interpretable time-series model with full predictive distributions is the goal. Use a hybrid approach when you want ML’s flexibility without abandoning an interpretable, theory-grounded structure.

The necessary caveat—supported by large forecasting competitions—is that complex models do not reliably beat simple ones, especially on the short, noisy series common in economics and business. Sophisticated ML can overfit and underperform a well-tuned exponential-smoothing model. So we never assume the complex model wins: we benchmark it rigorously out of sample against simple methods, and recommend the sophisticated approach only where it genuinely earns its place. More complexity is a hypothesis to be tested, not a given.

At a glance

Choosing an advanced forecasting approach

When each advanced approach fits
ApproachStrengthBest when
ML forecastingNon-linearity, many predictorsRich features, enough data to validate
Deep-learning forecastingSequences & many series at scaleLarge, high-frequency, multi-series data
Bayesian forecastingFull predictive distributions & priorsRigorous uncertainty; structural components
Hybrid econometric-MLFlexibility + interpretabilityBoth insight and accuracy needed
Simple baselines (ETS, ARIMA)Robustness; hard to beatAlways—as the benchmark
Methodology

Advanced, but disciplined

The flexibility that makes ML and deep learning powerful also makes them easy to misuse in a time-series setting, so the discipline is non-negotiable. Evaluation uses time-series cross-validation (rolling or expanding origins) that never shuffles the data—a random train/test split leaks future information and produces results that collapse in reality. Feature engineering must respect the time ordering (no look-ahead), and models are always compared against simple benchmarks (naive, seasonal-naive, ETS); a complex model that does not beat them is not used. Deep learning in particular needs sufficient data, and its appetite is matched to the series honestly rather than applied by default.

For Bayesian forecasting, the advantages come with their own requirements: priors are chosen and justified (and their influence checked), MCMC or variational estimation is assessed for convergence, and the resulting predictive intervals are checked for calibration—a 90% interval should contain the outcome about 90% of the time. A key strength is that Bayesian methods produce genuinely probabilistic forecasts, which we evaluate with proper scoring rules rather than point-accuracy alone. Across every approach, the same honest standard from classical forecasting holds: out-of-sample performance against benchmarks, with calibrated uncertainty, decides what is reported.

Complex does not mean better—prove it out of sample. Forecasting competitions repeatedly show sophisticated models failing to beat simple ones on short, noisy series. We benchmark ML, deep-learning, and Bayesian models against naive and ETS baselines with time-series cross-validation, and recommend complexity only where it genuinely wins.

Software

We deliver advanced forecasting in established, reproducible tools—Python (scikit-learn, XGBoost/LightGBM, PyTorch, sktime, darts) and R (fable, bsts, prophet, Stan via brms)—with time-series cross-validation, benchmark comparison, convergence and calibration checks for Bayesian models, and proper probabilistic scoring, all with versioned code.

How we work

How we deliver an advanced forecasting study

This work sits within our wider forecasting practice and draws on our machine-learning methods—so advanced models are used where they earn their place, and always benchmarked.

We start from the series, the predictors, and the goal—point forecasts, full predictive distributions, or many-series forecasting—and establish simple baselines first. We then build the advanced candidates (ML, deep learning, Bayesian, or hybrid) with time-ordered feature engineering and proper estimation, and compare everything out of sample with time-series cross-validation against the baselines.

Reporting sets out the baselines, the advanced models, the out-of-sample comparison, convergence and calibration evidence for Bayesian models, and the chosen approach with its justification—including, where honest, the finding that a simple model is best.

You receive the forecasts with calibrated uncertainty (predictive distributions for Bayesian models), the out-of-sample accuracy and benchmark comparison, the model and feature documentation, the diagnostics, clear visualisations, and reproducible analytical code and analysis-ready files (where appropriate and permitted).

Where we apply it

ML & Bayesian forecasting across research

Advanced forecasting adds value where non-linearity, scale, or rigorous uncertainty matter—across economics, finance, and business.

Macroeconomic Nowcasting

Combining many high-frequency indicators with ML or Bayesian methods to nowcast GDP and other aggregates.

Financial & Risk Forecasting

Volatility and risk forecasting and probabilistic market scenarios, with realistic expectations about return predictability.

Demand & Operations

Large-scale, many-series demand forecasting where ML and deep learning can exploit cross-series structure.

Energy & Commodities

Non-linear, driver-rich energy and commodity forecasting, often with hybrid models.

Policy & Scenario Analysis

Bayesian forecasts with full predictive distributions for decision-making under uncertainty.

Business & Marketing

Forecasting from rich behavioural and transactional data where non-linear ML methods add value.

FAQ

ML & Bayesian forecasting: common questions

Not reliably. Machine learning can capture non-linearities and many predictors that classical methods miss, but large forecasting competitions repeatedly show that sophisticated models often fail to beat simple ones—especially on short, noisy economic and business series, where ML can overfit. Which approach wins is an empirical question, settled by out-of-sample comparison against simple benchmarks, not by assuming the more complex model is better.
Deep learning (LSTMs, transformer-based forecasters) tends to pay off on large-scale problems—high-frequency data, long series, or many related series that share structure the model can exploit. It is data-hungry and prone to overfitting on short series, so it is rarely the right fit for a single, modest economic time series, where classical or simpler ML methods usually do as well or better. We match the method to the data rather than defaulting to the most complex option.
Bayesian forecasting produces a full predictive distribution rather than a single point, coherently propagating parameter and model uncertainty into the forecast intervals. It handles structural components (trend, seasonality, holidays) and the incorporation of prior knowledge elegantly, and gives genuinely probabilistic forecasts well suited to decision-making under uncertainty. It is especially valuable when quantifying and decomposing uncertainty matters as much as the point forecast.
Hybrid models combine an interpretable econometric or statistical backbone with the flexibility of machine learning—for example, using a classical model for the main structure and ML to capture residual non-linear patterns, or blending their forecasts. The aim is to get ML’s accuracy without wholly sacrificing interpretability. As with any approach, the hybrid is only adopted if it beats simpler alternatives out of sample.
By evaluating with time-series cross-validation (rolling or expanding windows) that respects the time ordering—never a random split, which leaks future information—engineering features without look-ahead, comparing against simple benchmarks, and keeping model complexity matched to the data. A model is only reported if it genuinely outperforms simpler alternatives on data it has not seen. These safeguards are what separate a real forecasting gain from an illusory in-sample one.
Not by point accuracy alone. Probabilistic forecasts—from Bayesian or other distributional models—are assessed for calibration (does a 90% interval contain the outcome about 90% of the time?) and with proper scoring rules (such as the continuous ranked probability score) that reward both accuracy and well-quantified uncertainty. We check that the stated uncertainty is honest, not just that the central forecast is close.

Need flexibility, scale, or rigorous uncertainty?

When non-linearities, many predictors, or full predictive distributions matter, ML, deep-learning, Bayesian, and hybrid methods extend what forecasting can do—and we benchmark every one honestly against simple baselines, so you adopt complexity only where it genuinely forecasts better.