A growth figure is announced. Within hours it is a headline, a speech, a chart and an argument. But what actually grew?

Not salaries. Not employment. Not household income - not necessarily any of them. GDP is one of the most influential numbers in public life and one of the most misunderstood, and most people are asked to trust it without ever being shown the working.

This book shows the working. It takes you to the statistical release itself and teaches you to read it: what GDP counts and what it leaves out, why nominal and real are different numbers, what happens when the base year changes and the ruler itself moves, how a first estimate becomes a revision - and where the honest line falls between a revision, a disagreement and a manipulation, because the three are not the same thing.

It names no political party anywhere. A claim is tested here against the release it came from; who made the claim changes nothing about whether the arithmetic holds.

Inside:
- The three ways one economy is measured, and why they should agree
- Base years, deflators, proxies and imputations, worked through in plain arithmetic
- Documented cases where countries really did falsify the numbers, and how it was caught
- How to download the official data and rebuild the headline yourself
- What GDP leaves out: inequality, unpaid work, natural capital, wellbeing
- Guided practice throughout, with worked solutions, a formula sheet, a source directory and a glossary

34 chapters, a bonus chapter and five appendices - an evidence-based guide for citizens.