What the index is for
The index is a screening tool for legislative and economic-development strategy. It is designed to help a district decide where to investigate additional business capacity, not to declare a market "good," "bad," "open," or "closed."
Methodology
The V1.0 score is frozen and this publication layer does not recalculate it.
Equal parts ZBP employer-establishment scarcity and NDS physical-establishment scarcity.
Weighted household-income proxy percentile.
Equal parts 10-year establishment, employment and nominal payroll growth.
What is ZBP?
ZIP Code Business Patterns (ZBP) is a U.S. Census Bureau business dataset that reports employer business activity by ZIP code, including employer establishments, employment and payroll. In this index, ZBP is used as one measure of employer-business supply and ten-year business growth.
Important: ZBP counts employer establishments. It is not a count of every business or self-employed person. The index also uses the separate NDS physical-establishment dataset as an additional business-supply measure.
What do the Supply Gap levels mean?
Supply Gap levels are relative to other districts in the same chamber. House districts are compared with House districts; Senate districts are compared with Senate districts.
| Level | Chamber position | Plain-language meaning |
|---|---|---|
| Very High Supply Gap | 80th percentile and above | One of the strongest signals of comparatively low business supply combined with stronger income capacity and business momentum. |
| High Supply Gap | 60th to below 80th percentile | Above-average evidence of a business supply gap. |
| Moderate Supply Gap | 40th to below 60th percentile | Near the middle of the chamber-relative distribution. |
| Low Supply Gap | 20th to below 40th percentile | Below-average evidence of a business supply gap. |
| Very Low Supply Gap | Below 20th percentile | One of the weakest chamber-relative supply-gap signals. |
A high Supply Gap is a relative market signal. It does not guarantee that a business will succeed, that a market is profitable, or that consumer demand is unmet.