Simulation-Based Empirical Bayes
Summary
Simulation-based empirical Bayes (SBEB) is a novel method for simultaneous inference across related latent variables when likelihoods are only available through a simulator. It extends classical empirical Bayes (EB) and simulation-based inference (SBI) by iteratively refining a nonparametric EB prior within an SBI loop. SBEB computes EB estimates without an explicit density, utilizing observed data, simulator samples, and an amortized inference network. The method demonstrates improved accuracy over fixed-prior SBI in various scientific simulators, including linear Gaussian, nonlinear static, oscillator, predator-prey, and evolutionary models. It also shows benefits in real-world applications like heterogeneous product choice and measles outbreak dynamics across 40 UK cities from 1944 to 1965.
Key takeaway
For research scientists developing models with intractable likelihoods and multiple related units, SBEB offers a robust approach to improve inference accuracy. You should consider implementing SBEB when a common population prior exists, as it learns this prior from data, outperforming fixed-prior SBI, especially with sufficient unit-level signal. Be prepared for increased computational cost and the need for an expressive amortized inference family.
Key insights
SBEB combines empirical Bayes and simulation-based inference to learn priors for intractable likelihoods.
Principles
- The SBEB update improves the fit of the induced marginal distribution.
- Prior KL divergence decreases, implying marginal convergence to the population.
- Prior identifiability ensures marginal convergence leads to prior convergence.
Method
SBEB iteratively approximates posteriors, averages them to refine an empirical Bayes prior, samples from this prior, simulates new data, and refits an amortized inference network.
In practice
- Infer city-specific epidemic parameters from measles time series.
- Estimate person-specific preference vectors in discrete choice models.
- Recover latent variables in complex scientific simulators.
Topics
- Empirical Bayes
- Simulation-Based Inference
- Intractable Likelihoods
- Amortized Inference
- Population Prior
- Epidemic Modeling
- Discrete Choice Models
Best for: AI Scientist, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by stat.ML updates on arXiv.org.