A RESEARCH ASSISTANT FOR DIFFERENCE-IN-DIFFERENCES

From questions
to evidence
you can explain.

Did a policy, program or business change make a difference? Develop the study in Claude or Codex, review the design, and explore the finding in a report that brings the data, estimates and checks together.

Private workspaces · Review before analysis · Invitation-only access

DID-ACTO / FROM THE SHARED SAMPLE LIBRARY

Did rent control
change the trajectory?

100 ZIP areas · 48 months · one common adoption date

Estimated monthly rent effect in the sample −$88.53, with a 95 percent confidence interval from −$92.58 to −$84.48. The horizontal axis includes zero. -100-75-50-250 Effect on monthly median rent ($)
Fitted TWFE estimate and 95% interval from the saved sample analysis.
−$88.53 per month95% interval
−$92.58 to −$84.48

Average effect on monthly median rent. Computed from a simulated practice dataset. Exploratory analysis; the walkthrough explains the comparison and checks.

Follow the sample from data to report →
Ask in plain languageReview before you runRevisit saved evidence

WHAT IT DOES

More than a before-and-after number.

A change after an intervention can have many explanations. DiD-Acto organizes a difference-in-differences study: comparing changes in exposed units with changes in an appropriate comparison group.

A better-defined question

Name the population, outcome, intervention, timing and effect you actually want to understand. The workflow asks for missing information instead of silently filling it in.

Understand the planning process →

Modern estimators, named

Callaway–Sant’Anna, Sun–Abraham, BJS imputation, extended TWFE, Gardner did2s, efficient GMM and synthetic methods—matched to the design and effect you want to study.

Explore estimators and tests →

Results you can interrogate

Ask how large the effect is, which observations contribute, and whether the checks suggest a different explanation. Revisit those answers in the saved report.

Learn to read the output →

BUILT FOR REAL RESEARCH QUESTIONS

Follow the change.
Examine the comparison.

Useful questions often start with a policy or operational change that affected some units earlier than others.

Policies & programs

Study whether an initiative changed an outcome across regions, institutions or eligible groups. Make rollout timing and other contemporaneous changes explicit.

Explore program evaluation →

Business rollouts

Investigate phased pricing, service or operational changes across locations. Separate the rollout from common market movements and changing composition.

Explore business analysis →

Academic & applied research

Move from panel data to an approved specification and a durable report. Keep the target effect consistent when comparing eligible estimators.

Explore research workflows →

Explore the data and design choices behind each study question.

THE WORKFLOW

Your assistant guides.
The server computes.
You decide.

Use the portal for files and accounts. Use Claude or Codex to work through the research conversation. DiD-Acto checks and executes the analysis behind the scenes.

Walk through the process →
  1. 01

    Register

    Connect the dataset to your question.

  2. 02

    Inspect

    Understand what the data can support.

  3. 03

    Plan

    Make the choices before the fit.

  4. 04

    Run

    Execute the approved analysis.

  5. 05

    Interpret

    Read the evidence in context.

  6. 06

    Report

    Keep a record you can revisit.

WHAT YOU TAKE AWAY

An evidence package.
A clearer next decision.

Your result can include an overall or dynamic effect, uncertainty, support information and checks appropriate to the approved method. The report brings the study question, estimates and diagnostic findings together in one place.

See what the evidence says, where the answer is still uncertain, and which follow-up would be useful.

Explore an example report
01 / THE ESTIMATE

How much changed?

Read the exact target, outcome scale and time window.

02 / THE EVIDENCE

How much can you conclude?

Inspect uncertainty, comparisons and design limitations.

03 / THE RECORD

Can you explain it later?

Return to a saved result and download its report bundle.

A WORKSPACE FOR YOUR TEAM

Private research.
Shared starting points.

Your own files

Uploads and analysis results are private from other analysts. Authorized administrators can review them.

A sample library

Shared datasets are read-only. Use them to learn the workflow before working with your own study.

Account control

Sign in with a dedicated account, change your password, and return to your saved files and reports.

Clear operating limits

The current service supports files up to 200 MB and a 2 GB workspace per analyst. Analysis jobs may queue.

Files and analysis run on our server. Your AI provider processes the tool results you request through your assistant. Read the privacy and limits guide.

IS IT A FIT?

Good evidence starts with a suitable question.

DiD-Acto is most useful when you can explain what changed, when it changed, who was exposed and why the comparison is credible.

Bring these ingredients

  • An outcome observed across units and time.
  • Identifiable treatment timing and a plausible comparison group.
  • Knowledge of the assignment process and possible confounders.
  • A clear view of the effect size that would matter in practice.

Bring your knowledge of the intervention; DiD-Acto helps translate it into a study you can inspect and explain.

Understand what is supported →

YOUR FIRST QUESTION STARTS HERE

Bring a question.
Build the evidence.

Start with a shared sample, learn the workflow, then bring your own data.