# Identify Antitrust Issues In Counterpartys Expert Economic Report > Closes gaps in econometric specification critique including residual diagnostics, structural-break testing, methodological linkage to prior exclusion history, and consistency analysis between affected-commerce measures and market-share evidence. - Skill: `finchipaiorg/identify-antitrust-issues-in-counterpartys-expert-economic-r` (Agent Skill) - Install (CLI): `npx skillmds@latest add finchipaiorg/identify-antitrust-issues-in-counterpartys-expert-economic-r` - Raw SKILL.md: https://api.skillmd.com/api/skills/finchipaiorg/identify-antitrust-issues-in-counterpartys-expert-economic-r/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Docs & Writing - Author: FinchipAIOrg (https://skillmd.com/u/finchipaiorg) - Updated: 2026-09-22 - Page: https://skillmd.com/skills/finchipaiorg/identify-antitrust-issues-in-counterpartys-expert-economic-r --- # Skill: Expert Economic Report Critique ## 1. Subject-matter triage - Treat the task as an issue-spotting memorandum against an opposing expert economic report, not a merits brief. - First identify the governing antitrust theory, damages theory, and the expert’s stated method; then test the report on its own assumptions, data inputs, and cited sources. - Separate pure econometric defects from factual inaccuracies, legal mismatches, and impeachment material; do not merge them into one generalized criticism. - Enumerate each defendant, period, product set, market, and damages slice that is materially distinct before analysis; do not assume one pass fits all when the report uses multiple datasets or time windows. - If the report is only about one model, state that expressly and analyze that model by its distinct specifications and outputs. ## 2. Failure modes the skill is correcting - The critique stops at broad disagreement and does not isolate the exact methodological defect, data defect, evidentiary gap, or legal mismatch. - The critique misses whether the regression is internally testable on the face of the report, including residual diagnostics, specification choices, and sensitivity checks. - The critique overlooks whether the expert assumed a conspiracy period instead of testing it, creating a cross-examination point on arbitrariness. - The critique fails to compare defendant-specific affected-commerce figures against other market evidence that should be directionally consistent. - The critique does not tie the expert’s methodology to any prior exclusion, limitation, or criticism of the same methodology where that history is relevant to admissibility. - The critique flags a problem without showing scale, interaction with other materials, or litigation consequence, leaving the issue underdeveloped. - The critique omits a concrete rebuttal path, making it harder to convert the critique into targeted cross-examination or Daubert practice. ## 3. Legal frameworks / domain conventions that apply - Daubert v. Merrell Dow Pharmaceuticals, Inc.; Federal Rule of Evidence 702: expert testimony must rest on sufficient facts, reliable principles and methods, and reliable application. - Federal Rule of Evidence 703: the expert’s factual inputs must be of a kind reasonably relied on by experts in the field. - Federal Rule of Evidence 403: overbroad or misleading econometric presentations can be attacked where probative value is outweighed by confusion or unfair prejudice. - Antitrust damages models should be assessed for specification error, omitted-variable risk, unsupported causal assumptions, and failure to test key breakpoints. - Residual diagnostics matter: autocorrelation, heteroskedasticity, and related misspecification concerns can undermine inferential reliability. - Structural break analysis matters when the model hard-codes an alleged conspiracy start date rather than testing whether the data support that date. - A single binary conspiracy indicator can be a simplifying assumption, but it is vulnerable where participation, timing, or conduct differs materially across defendants or across time. - Internal consistency across the report, exhibits, underlying data, and cited market evidence is a standard impeachment axis; arithmetic errors are especially useful because they are verifiable on the page. - Prior methodological criticism of the same expert or same model family can be relevant to reliability and to the weight, and sometimes admissibility, of the opinions. - Where the report implicates pass-through, market definition, or class-period assumptions, the critique should tie those assumptions to the controlling factual record and the applicable damages theory. ## 4. Analytical scaffolds 1. Map the report: - Identify the expert, the opinion being offered, the model type, the data universe, the relevant period, and the stated damages or liability theory. - List each distinct defendant, product, market, and time span that the report treats separately. 2. Test the method: - Check whether the model explains variable selection, functional form, and identification strategy. - Look for residual autocorrelation, heteroskedasticity, multicollinearity, overfitting, selection bias, and failure to test alternative specifications. - Flag missing robustness checks, but only when the report’s own design makes those checks material. 3. Test the timing: - Determine whether the claimed start of the unlawful period is empirically tested or merely assumed. - Compare the expert’s period assumptions with the operative factual record and any competing period definitions in the source materials. - If the report uses a single period for all defendants, test whether the record supports uniform treatment. 4. Test defendant-level consistency: - Compare affected-commerce measures, output shares, sales shares, or other defendant-level allocations against market-share evidence or comparable record evidence. - Identify materially divergent treatment across defendants and explain why the divergence suggests a method issue, not just a factual dispute. - If the report aggregates defendants, assess whether aggregation obscures meaningful differences in conduct or exposure. 5. Test arithmetic and exhibits: - Recompute reported totals, shares, averages, and tables from the underlying exhibits. - Flag any mismatch between narrative, chart, table, appendix, and source data. - State the correct figure or the correct direction of the error when the underlying materials permit it. 6. Test omitted variables and controls: - Identify obvious omitted variables, alternative causal drivers, supply-side constraints, demand shocks, regulatory events, or product differences the model should have addressed. - Explain whether the omission likely biases the estimate upward, downward, or in an ambiguous direction. 7. Test admissibility history: - If the same expert, same framework, or same core technique was criticized, limited, or excluded before, connect that history to the current methodology rather than treating it as background color. - Focus on the shared defect: unsupported assumption, weak identification, misuse of data, or overstatement of causal inference. 8. Test legal fit: - Check whether the opinion matches the relevant antitrust theory, class period, injury theory, and damages construct. - Identify places where the expert’s legal assumptions exceed what the record or governing theory permits. ## 5. Vertical / structural / temporal relationships - Use a vertical hierarchy: report-wide defects first, then model-specific defects, then defendant-specific or exhibit-specific defects, then line-item arithmetic errors. - Use a temporal sequence: pre-period baseline, alleged violation period, post-period validation, and any break date or transition period. - Where the source materials include multiple defendants or multiple products, analyze each separately before synthesizing. - Where the report compares one measure to another, analyze the direction and magnitude of the inconsistency, then explain the doctrinal or economic significance. - If the report’s conclusion depends on a chain of assumptions, identify the weakest link and the downstream assumption that fails with it. ## 6. Output structure conventions - Write a memorandum with a clear issue register, not a narrative essay. - Define one ordinal severity scale at the outset and apply it consistently to every issue. - Give each issue a unique identifier and keep the issue description concise but specific. - For each issue, include: - severity - issue statement - why it matters - source support or conflict - cross-examination angle - rebuttal recommendation - Close every issue by tying it to scale, interaction with another source item, and the litigation consequence. - Include a short summary table that lists all issues and severities before the detailed analysis. - Include a legal authority section that names the controlling admissibility authorities relied on. - End with a Recommended Actions block that gives concrete next steps, assigns the responsible role, and anchors timing to the briefing, deposition, expert-discovery, or motion schedule where available. - Use precise legal citations when stating admissibility propositions; do not state reliability conclusions without naming the governing rule or case.