🤖 AI Summary
In likelihood-intractable scenarios, Approximate Bayesian Computation (ABC) faces key bottlenecks: difficulty in selecting informative summary statistics, complex tuning of distance metrics and tolerance thresholds, high computational cost, and substantial posterior uncertainty due to weak prior information. To address these challenges, this paper proposes ABC-SMC-(D)RF—a novel method integrating Distributed Random Forests (DRF) into the Sequential Monte Carlo (SMC) framework for the first time. It enables end-to-end learning of discriminative features, eliminating manual design of summary statistics and distance functions. Coupled with adaptive tolerance scheduling and a pre-acceptance shrinkage mechanism, it iteratively concentrates sampling on high-probability parameter regions. Experiments across diverse deterministic and stochastic models demonstrate significant improvements in posterior estimation accuracy and robustness; notably, stability under weak priors is markedly enhanced, and computational efficiency surpasses that of conventional ABC-RF.
📝 Abstract
Approximate Bayesian Computation (ABC) is a popular inference method when likelihoods are hard to come by. Practical bottlenecks of ABC applications include selecting statistics that summarize the data without losing too much information or introducing uncertainty, and choosing distance functions and tolerance thresholds that balance accuracy and computational efficiency. Recent studies have shown that ABC methods using random forest (RF) methodology perform well while circumventing many of ABC's drawbacks. However, RF construction is computationally expensive for large numbers of trees and model simulations, and there can be high uncertainty in the posterior if the prior distribution is uninformative. Here we adapt distributional random forests to the ABC setting, and introduce Approximate Bayesian Computation sequential Monte Carlo with random forests (ABC-SMC-(D)RF). This updates the prior distribution iteratively to focus on the most likely regions in the parameter space. We show that ABC-SMC-(D)RF can accurately infer posterior distributions for a wide range of deterministic and stochastic models in different scientific areas.