The Guinndex
The Guinndex is a public price index for a pint of Guinness, built by having an AI voice agent phone the pubs of Ireland and the UK and ask what a pint costs. It has reached 52,759 pubs and holds 8,732 verified prices. Within days of publication, pubs named as expensive began cutting their prices.
Official inflation statistics are built from careful baskets and feel distant from everyday life. The price of a pint is the opposite: immediate, remembered, argued about. The Guinndex turned that into a measure, what one columnist called a "lived inflation" index, by having an AI agent do something no researcher could: ring every pub in the country and just ask.
The pipeline: a voice agent (built on Twilio and modern speech models) that navigates landlines, hold music and skeptical bartenders; verification and de-duplication of every quoted price; and an open map at guinndex.ai. Within days of publication, pubs named as expensive began cutting their prices, a market responding to its own measurement.
Then came the sequel. The UK edition at guinndex.co.uk ran the same method at several times the scale: 46,235+ pubs across 104 regions, 6,548 verified prices, a £5.82 average, and a London cheapest-pints map. The same phone network went on to carry The World Cup Index, a Twilio collaboration, which put the index back in the papers for a second wave.
Both indices are still running, and no longer only by phone. Readers now correct and extend them: 1,830 contributions to date. The agent gets the first number, the crowd keeps it honest.
Frequently asked
How were the prices collected?
An AI voice agent phoned each pub and asked the price of a pint of Guinness. It says it is an AI at the start of every call. Readers can also submit and correct prices, so the index keeps improving after the calls.
How accurate is it?
Every price is a real answer given by a real person, verified and de-duplicated, and dated to when it was collected. Prices change, so any single figure is a snapshot. We publish the method alongside the numbers so you can judge them.
Which areas does it cover?
All 32 counties of Ireland and 104 regions across the UK. 52,759 pubs in total.
Does the AI pretend to be human?
No. On the Guinndex the agent discloses that it is an AI at the top of every call and answers honestly if asked.
Did it actually change prices?
Yes. Within days of the first publication, pubs named as expensive began cutting their prices. It was covered by BBC News, Fortune, The Times, The Guardian and Vice.
Can I look up a specific pub?
Yes, at guinndex.ai for Ireland and guinndex.co.uk for the UK.
Can you build an index like this for our market?
Yes. If there is a price the public pays that nobody measures, that is the kind of study we run. Email hello@primedirective.ai.