# By the Numbers

> Using data and research to understand what really makes a difference.

- **Platform:** substack
- **Category:** Science
- **Subscribers:** 72K
- **Weekly growth:** +0.7%
- **Monthly growth:** +1.2%
- **Last updated:** 2026-05-15
- **URL:** https://hannahritchie.substack.com
- **Profile:** https://newsletterinsights.io/newsletter/hannahritchie