Contact

BigMacIndex.app is run by one person — Robert. W, an independent developer based in Australia — so there is no support team and no ticketing system behind that address. That has one advantage worth using: a well-formed email gets a real answer from the person who maintains the data, usually including the reasoning behind whatever number you are asking about. The sections below say what to include for each kind of message, because the difference between a report we can act on and one we cannot is almost always two or three missing details.

Reporting a price that looks wrong

This is the most useful email we get. Prices on this site come from three different kinds of source — The Economist's twice-yearly survey, our own country research, and reader observations — and the methodology page explains how each is handled. To check a report against those rules, we need:

• The country, city and restaurant. A price without a location cannot be interpreted; prices inside a single country vary by tens of percent.
• The price of a standalone Big Mac — not a meal, not a combo, not an app promotion or coupon price. If your receipt only shows a meal, say so and we will treat it as context rather than as a price observation.
• The currency and the exact date you saw or paid it.
• Whether it was dine-in, takeaway or delivery, since these are often different prices with different tax treatment.
• Something checkable. A link to the local McDonald's menu or delivery site is ideal. A photograph of the till receipt or the in-store menu board is the next best thing. A remembered number is still welcome, but it will be recorded as unverified.

What happens next: a report that meets those conditions is published as an annotation on the relevant country page, credited to you. It normally does not overwrite the published headline figure, and that is deliberate rather than dismissive — the reasoning is set out in full under reader price reports. Reports that confirm our figure get published too; a physical receipt agreeing with a desk-research estimate is the strongest validation we can get. If the published number turns out to be an outright error — a typo, a wrong unit, a misaligned row — it gets fixed rather than annotated, and the fix is credited.

On receipts: we do not publish a receipt image unless you explicitly agree to it. When we do, the payment block, card issuer, terminal number, exact transaction time and any staff identifiers are redacted first. That slip is a record of your purchase, not our stock photography.

Reporting a bug or a broken link

The site is built and tested by one person, so browser-specific and device-specific problems are the ones most likely to survive to production. If something is broken, the following makes it reproducible:

• The full URL of the page where it happened
• Your browser and version, and whether you were on a phone, tablet or desktop
• What you expected to happen, and what happened instead
• A screenshot, if the problem is visual — a chart that will not render, a table that overflows sideways, a map that stays blank

Broken or outdated links are worth reporting on their own. Many country pages cite local news articles and official menu pages, and those sources move or disappear over time; a dead citation is a data-quality problem, not just a cosmetic one.

Using the data

The processed dataset is published on the data download page in CSV and JSON, and you are free to use it for research, journalism, coursework and personal analysis with attribution to BigMacIndex.app. You do not need to ask first for that.

Do write if you want to discuss commercial redistribution, need a cut of the data in a different shape or cadence, or want to confirm how a figure was derived before citing it. One thing we cannot grant: the underlying Big Mac price series belongs to The Economist, and licensing questions about that series have to go to them, not to us. Our own editorial country research is a different matter — tell us where it will appear and what you need.

If you are asking about an API rather than a file, there is a waitlist page; joining it tells us more about demand than an email will.

Media and partnerships

For interviews, data requests to accompany an article, or collaboration proposals, include who you are writing for, your deadline, and the specific numbers or cuts of the data you need. Deadlines are respected where physically possible, but this is a side project — if you need something within hours, say that in the subject line.

This site takes no sponsored placements and does no paid consulting, so proposals of that kind will be declined politely and quickly.

Legal, privacy and takedown requests

Matters relating to the Terms of Service or the Privacy Policy, including requests to remove personal information, go to [email protected]. Requests of this kind are handled ahead of everything else in the queue.

When to expect a reply

The inbox is checked most days. Most emails are answered within a few working days; a price report that needs a source cross-checked can take longer, because the checking is the slow part. Every genuine message gets a reply, including reports where we end up keeping the existing number — in that case the reply explains why, rather than going silent.

If a week has passed with nothing back, resend. Mail from a new address occasionally lands in spam, and a resend is far more likely to work than assuming the first one was ignored.

Your privacy when you write

Emails sent to this site are not published, quoted publicly, or shared with third parties, and there is no mailing list to be added to. Correspondence is kept only as long as it is useful for the correction it relates to.

If your report is published as an annotation, you are credited by first name only by default. Writing to us is not consent to have a full legal name permanently indexed by search engines, so the reply will ask how you would like to be credited — full name, first name plus an initial, first name only, anonymous, or with a link to your own site — and the conservative default stays in place until you answer. If you would rather not be credited at all, say so and the observation is published without any attribution. You can also ask for a credit to be changed or removed later.

Full details of what the site collects from ordinary browsing are in the Privacy Policy.