Explainer
Commercial and tribal gaming revenue: what to compare
The short answer
A total belongs to the population and definition used by its source. Combining reports requires evidence that their coverage, periods, and accounting measures are compatible and do not overlap.
In this article
A pair of impressive totals invites a simple addition. But arithmetic can only answer whether the numbers were added correctly. It cannot establish that they should have been added in the first place. That second question belongs to the source notes.
Population is part of the measure
The NIGC FY 2024 release is explicitly about tribal gaming revenue. It should retain that scope when cited. A separate report describing commercial activity must be read on its own terms; a similar-looking revenue label does not prove identical coverage or measurement.
Illustrative example
| Check | Reason |
|---|---|
| Coverage | Identify the included operations and activities |
| Overlap | Avoid counting an activity twice |
| Period | Align the time windows |
| Measure | Confirm that revenue definitions are compatible |
| Revisions | Use the appropriate version of each series |
An overlap example with visible arithmetic
In a fictional dataset, report A includes ten units and report B includes eight. Three units appear in both. Adding the displayed totals gives eighteen; counting each unit once gives fifteen. Without the overlap information, an analyst cannot choose between those interpretations simply by looking at the two headline totals.
Coverage gaps create the opposite problem. If a category is absent from both reports, adding them still leaves that category out. A calculated sum should therefore be named for what it actually includes, rather than given a broad “entire market” label by default.
Make an honest comparison useful
When compatibility cannot be established, present the series side by side. Name each reporting body, reproduce its scope, and explain why a combined figure is unavailable. Readers can still learn from separate trends without being asked to trust an unsupported national total.
A short note under a chart can do more work than another decimal place: “different reporting populations; totals have not been combined” explains the boundary directly. Preserve links to the original releases so that a later revision can be traced.
