# Stanford Graduate School of Business — 2026-10-08T00:00:00.000 (am a research assistant at Stanford Graduate School of Business, independently conducting research on concentration among large municipal business taxpayers and city revenue risk. San Francisco and Kent, Washington have provided annual 

**Score:** 76/100

| Field | Value |
|---|---|
| Organization | Stanford Graduate School of Business |
| Filing Date | 2026-10-16 |
| Jurisdiction | IL |
| Locality | am a research assistant at Stanford Graduate School of Business, independently conducting research on concentration among large municipal business taxpayers and city revenue risk. San Francisco and Kent, Washington have provided annual disclosure-safe measures of taxpayer-payment concentration: HHI (10,000 times the sum of squared taxpayer shares), the top ten taxpayers' combined share, and annual business-tax receipts. I am seeking a comparable measure for Chicago, while recognizing that Chicago does not administer the same broad gross-receipts tax as those cities. Could your Department identify a suitable Chicago-administered business tax or fee with taxpayer-level payment records and, if feasible, provide an existing disclosure-safe top-ten share or HHI for 2019–2024 (or even one recent year)? Alternatively, could you direct this research inquiry to the relevant Tax Collection and Enforcement or revenue-analysis staff to explore whether an internal aggregate calculation is permissible? I do not seek taxpayer identities, individual payments, or confidential returns. This is an inquiry about the availability of aggregate statistics, not a request for protected taxpayer records. Please let me know if a formal FOIA process is appropriate for any existing nonconfidential records. |
| Classification | 2026-10-08T00:00:00.000 |
| Reported Metric | Arnav Singhal |
| Dataset Source | Chicago Data Portal (7avf-ek45) |

## Why this score
- Official Chicago Data Portal commercial filing (7avf-ek45)
- Verified organizational registry record
- Recent filing window (2026-10-16)
- Jurisdiction: IL

Source: Chicago Data Portal — FOIA Request Log (7avf-ek45) (https://data.cityofchicago.org/d/7avf-ek45). Last refreshed: 2026-11-04T06:11:35.432Z.
Source: Chicago Data Portal (data.cityofchicago.org, dataset 7avf-ek45). Public registry publication is a routine administrative record and is not a finding of fault, violation, or noncompliance. Individual and sole-proprietor records are excluded; verify directly with the issuing agency before taking action.