Model-to-World · Simulation for Decision-Making

From simulated worlds to reliable decisions in the real one.

M2W builds decision-focused models of complex systems, tests policies in plausible and consequential worlds, and measures what may fail when a model meets reality.

Decision Lab 01 Live

Assortment under customer substitution

When less shelf space makes more revenue.

Expected revenue$79.98per synthetic visitor
Run the decision

The M2W research loop

Build a world. Make a decision. Learn what survives.

The model-to-world gap is not a final disclaimer. It is measured throughout the decision process and updated with evidence from reality.

  1. 01Model

    Represent the mechanisms, constraints, and uncertainty that shape a consequential system.

  2. 02Simulate

    Explore ordinary, rare, shifted, and counterfactual worlds before acting in the real one.

  3. 03Decide

    Compare policies and optimize performance while accounting for uncertainty and misspecification.

  4. 04Transfer

    Test what survives the model-to-world gap, then validate and recalibrate with new evidence.

Audit the model-to-world gap
José Blanchet
José H. BlanchetProfessor of Management Science & Engineering

A personal journey

From Oaxaca to Stanford—with probability along the way.

I grew up in Oaxaca, Mexico, where a high-school course first drew me to probability and statistics. Because applied mathematics was not available locally, I moved to Mexico City to study applied mathematics and actuarial science at ITAM.

At ITAM I also met my wife, Citlalli (“Lalli”), in Algebra I. We later came to the Bay Area for graduate school—me at Stanford and Lalli at Berkeley. That journey, from an early encounter with probability to a career building models for consequential decisions, is part of the story behind M2W.

Continue the story Stanford profile

See it in action

Decision Labs turn methods into testable objects.

Change a decision, hold the modeled world fixed, and see the consequences. Every lab states what is synthetic, what is observed, and what remains to be validated.

Decision Lab 02 · LiveThen remove knowledge of the world—and learn the decision from logged choices.

Compare repetitive incumbent data with designed exploration and a pessimistic learner.

Explore all Decision Labs

Research

The mathematics inside the loop.

Probability, simulation, causal inference, and optimization work together to make the model-to-world gap measurable and decisions more reliable.

01

Model

Represent the mechanisms, constraints, and uncertainty that shape a consequential system.

  • Stochastic systems
  • Data-derived models
  • Causal structures
02

Simulate

Explore ordinary, rare, shifted, and counterfactual worlds before acting in the real one.

  • Monte Carlo
  • Rare-event simulation
  • Generative worlds
03

Decide

Compare policies and optimize performance while accounting for uncertainty and misspecification.

  • Robust optimization
  • Learning and control
  • Policy evaluation
04

Transfer

Test what survives the model-to-world gap, then validate and recalibrate with new evidence.

  • Sensitivity analysis
  • Out-of-sample guarantees
  • Closed-loop diagnosis
Explore the M2W research program

Selected foundations

A research trajectory built for M2W.

Representative work connecting model discrepancy, computation, and decision performance.

People

Blanchet Research Group

Researchers working across probability, optimization, machine learning, causal inference, and stochastic systems.

View the full group & alumni

Recent work

Latest publications

Automatically synchronized
2026

Extending Subsampling to Sequential Stopping

arXiv

2026

There and Back Again: Bidirectional Diffusion Bridges for Multimodality Translation

arXiv

2026

Sobolev Regularized Score Difference Estimation in Diffusion Models

arXiv

Browse all 349 publications

Funding & collaboration

Research made possible through partnership.

We gratefully acknowledge the agencies and collaborators supporting the group’s research and training.

View Funding & Support