Electrical Materials Index methodology
The automated pipeline normalizes every available component to 2026-01 = 100, applies the configured weights, and sums the results. This table renders from the computation config.
| Component | Series | Weight | Failure handling | Validation |
|---|---|---|---|---|
| Copper wire and cable | WPU10260314 | 35% | Retain prior period | Validated automatically |
| Steel mill products | WPU1017 | 15% | Automatic proportional reweighting when permitted | Validated automatically |
| Transformer manufacturing | PCU335311335311 | 20% | Automatic proportional reweighting when permitted | Validated automatically |
| Electrical equipment manufacturing | PCU3353 3353 | 15% | Automatic proportional reweighting when permitted | Confirmation pending; candidate PCU33533353 |
| Construction average hourly wage | CES2000000003 | 15% | Automatic proportional reweighting when permitted | Validated automatically |
Weighting rationale
The index combines conductive material, structural metal, equipment manufacturing, and construction wage movement. It measures national input movement rather than installed project cost or code compliance.
Revisions, degraded mode, and staleness
Published period files never change. Later revisions are recorded in a new period while the original base stays pinned. A non-critical failure may be reweighted when unavailable weight is at most 33.3%. A critical failure or larger gap retains the prior period. At 75 days the date is replaced by “Index data refresh pending”; at 120 days the landing page reports interrupted collection.
Limitations
The EMI does not measure retail markup, regional labor, installation conditions, equipment specifications, permits, taxes, or electrical-code compliance.