Moran's I report
Spatial autocorrelation results across the SSA-derived corpus.
Namesake·Reports·source: people-analyst/baby-namer/docs/research/reports/moran_report.md
title: "Geographic Diffusion and Moran's I" description: "Spatial autocorrelation of naming patterns across U.S. states, 1960–2024." publishedAt: "2026-04-13" status: published authors: ["Namesake Research"] category: report
5.10 Geographic Diffusion and Moran's I
Spatial Autocorrelation Over Time
Mean Moran's I across 65 years (1960-2024) for top 200 names:
| Decade | Mean Moran's I | Interpretation |
|---|---|---|
| 1960s | 0.5149 | positive autocorrelation |
| 1970s | 0.4569 | positive autocorrelation |
| 1980s | 0.4353 | positive autocorrelation |
| 1990s | 0.4076 | positive autocorrelation |
| 2000s | 0.3761 | positive autocorrelation |
| 2010s | 0.3226 | positive autocorrelation |
| 2020s | 0.2676 | positive autocorrelation |
Pre-streaming mean I: 0.4285, Post-streaming mean I: 0.2906. Spatial autocorrelation has decreased in the streaming era, consistent with more uniform national exposure displacing regional diffusion patterns.
Event Diffusion Velocity
Analyzed 11 top events:
- First adopter was coastal: 100% of events
- First adopter was top media market: 100% of events
- Mean states adopting within 3 years: 21.6
Coastal vs Interior Adoption
Coastal states mean change: 4.30 (n=1260) Interior states mean change: 1.54 (n=1285) t=2.07, p=0.0390
Significant coastal advantage in cultural name adoption.