You’ve built a case on clean, compelling data. You’ve got the trends, the metrics, the story. But what if that story is incomplete—or worse, misleading?
In high-stakes litigation, attorneys often rely on aggregated data to prove or defend against claims. But beneath those polished averages could be a statistical trap that even seasoned litigators and experts overlook. It’s called Simpson’s Paradox, and it’s more than a math problem—it’s a legal landmine.
At Ampcus Forensics, we’ve seen how this subtle paradox has unraveled arguments, disqualified expert testimony, and flipped the narrative in depositions and courtrooms alike. This article breaks it down—clearly, practically—and shows how you can protect your case by asking the right questions and using the right tools.
⚖️ Simpson’s Paradox, Simply Put
Simpson’s Paradox occurs when a trend in aggregate data reverses when the data is broken down into smaller groups.
Let’s say you’re handling a gender discrimination case. Your top-line data shows men are promoted at a higher rate. But when you break it down by department, women are actually being promoted more often.
One dataset. Two opposite conclusions.
That’s the paradox.
Where This Paradox Plays Out in Your Practice
- Employment Discrimination
Imagine you’re reviewing a company’s promotion history. On the surface, it looks like systemic bias. But once disaggregated by department, function, or geography, the alleged disparity evaporates—or flips.Forensic team insights: Never rely on averages alone. Ask your experts to stratify. You may be fighting a ghost—or missing a winning angle.
- Consumer Class Actions & Damages
Plaintiffs claim overcharges across multiple regions. The average supports certification. But deeper analysis shows overcharges were isolated—and some areas were actually undercharged.Forensic team insights: Courts are watching. Broad averages can invite Daubert challenges or create grounds for reversal on appeal.
- Breach of Contract
Your client claims lost revenue post-breach. Total profits dropped—but specific product lines performed better. The shift in mix—not the breach—drove the dip.Forensic team insights: Causality matters. Make sure your expert dissects performance by business driver, not just headline results.
⚖️ Courts Are Already Ruling on It
You’re not arguing in a vacuum. Courts are increasingly cautious of aggregated data:
- Bates v. UPS (2007): Disparity in disability accommodations vanished when segmented by department.
- Wal-Mart v. Dukes (2011): The Supreme Court refused class certification based on generalized statistics.
Judicial trend: If your data isn’t granular, it isn’t persuasive.
🔍 So, What Should You Do?
Here’s what smart litigators are already doing—and what we help our clients do every day:
- Bring Experts in Early
Let your forensic accountant or statistician flag confounding variables before they show up in a deposition or motion. - Demand Methodological Rigor
Challenge opposing experts who ignore subgroup effects. Defend your own by showing deep, deliberate analysis. - Visualize the Discrepancies
Courts don’t love complexity. Show them how the data shifts using simple visuals. Confusion never wins. - Align Your Data with Your Theory
Make sure your experts understand not just the numbers—but the legal strategy. Disaggregated data strengthens narrative.
👁️ Why Ampcus Forensics?
We’re not just number crunchers—we’re strategic partners for attorneys. At Ampcus Forensics, our team of certified experts:
- Spots data traps early
- Builds rock-solid damages models
- Prepares courtroom-ready reports and visuals
- Helps litigators feel confident in discovery, deposition, and trial
We’ve been in the trenches—supporting law firms across industries, case types, and jurisdictions. And we know that in litigation, it’s not about having data. It’s about understanding it.
💬 Final Word: The Numbers Don’t Always Tell the Truth—But We Can Help You Find It
Simpson’s Paradox is a silent threat. But for attorneys who recognize it, it’s also a strategic edge. Knowing how to navigate misleading trends can be the difference between winning a case and missing a critical angle.
Want to talk through a tricky dataset? Facing questionable stats from opposing counsel?
Let’s connect.
Because at Ampcus Forensics, we turn complex data into courtroom clarity.