The Espresso Index

Income inequality, explained from the research.

A nonpartisan guide to what economists and political scientists have actually found — 22 foundational papers and books, every claim sourced, every citation count verified, and the open debates presented as open. We take no policy positions.

Citizens

Start with the basics

Is inequality actually rising? How is it measured? Plain-language explainers, every fact traceable.

Learn the basics

Researchers

Search the library

A verified bibliography with plain and technical summaries, contested-finding flags, and sourced citation counts.

Open the library

Educators & media

Grab ready-made resources

Reading lists by audience and balanced framing of the field's real debates, built for lesson plans and articles.

Browse resources

How we stay trustworthy: every citation count shows where it came from and when it was checked — or says plainly that it hasn't been verified. Contested findings link to a page presenting each side. Read our editorial standards. Want to chart inequality against espresso prices? The Data Lab has the top-10% income share loaded.