How to Choose an Antitrust Economist Expert Witness for Merger and Cartel Cases

Choosing the right antitrust economist can make or break a complex merger or cartel matter. This guide explains when to engage an expert, what to look for, the typical scope of work, and practical questions to vet candidates efficiently.

When to engage an expert

Hire an economist early when the case will hinge on market definition, competitive effects, or damages. Early engagement helps shape strategy, guide discovery, and preserve key evidence. Common triggers include:

• Merger filings with significant market share changes.
• Allegations of coordinated conduct or cartel damages.
• Complex economic issues such as two-sided platforms, bundling, or vertical restraints.

Engaging before finalizing legal theory allows the expert to influence data requests and model selection, and to estimate potential remedies.

What credentials and experience matter

Look beyond job titles. The strongest experts combine rigorous academic training with practical case work in competition matters. Important signals include:

• Advanced degree in economics, with specialization in industrial organization or antitrust.
• Track record as a retained expert in merger control, cartel damages, or platform cases.
• Published research or conference presentations on relevant topics.
• Experience testifying at deposition and trial, including cross-examination.
• Familiarity with tools such as merger simulation, price-concentration analysis, and demand estimation.

Also prioritize candidates who can explain technical analysis clearly to judges and juries.

Typical scope, process, and deliverables

Most engagements follow a predictable workflow, which helps you budget and plan.

• Scoping and data review, including identification of key datasets and initial plausibility checks.
• Interim analyses, sensitivity checks, and iterative discussions with counsel.
• Drafting the expert report, with clear methodology, assumptions, and results.
• Depositions and trial testimony, including slides and demonstratives.

Deliverables to expect: written expert report, exhibits and code appendix, deposition preparation materials, and courtroom-ready visual aids.

Questions to ask, and red flags

Ask direct questions during the vetting call:

• Have you handled cases with similar facts and market structure?
• Do you have recent deposition or trial experience?
• What data will you need, and who will run the analyses?
• Can you provide anonymized case examples or references?

Watch for red flags: vague methodology, inability to name comparable cases, or lack of experience with the specific market or data types.

Selecting an expert is a strategic decision. Prioritize clear communication, demonstrable methods, and courtroom readiness. If you want, we can help draft a short scoping checklist to send to prospective economists, tailored to merger or cartel matters.