How to read inflation data without getting fooled

If you read three news outlets on any given inflation-data day, you'll see three different framings — sometimes opposite — of the same release. That's not always bias. Some of it is just that "inflation" describes several different things, and reporters pick whichever metric supports the angle they want.

Here's a short field guide for reading inflation data like someone who isn't being sold anything.

The four numbers people mean when they say "inflation"

1. Headline CPI (year-over-year) — The Consumer Price Index, all items, compared to twelve months ago. This is what the BLS reports each month. It's a percentage, e.g. "CPI rose 3.2% in March."
2. Core CPI — Same thing, with food and energy stripped out. Used because food and energy are volatile and can mask underlying trends.
3. Month-over-month CPI — How much prices moved last month, annualized or not. Useful for spotting turning points, easy to over-interpret.
4. Specific item prices — What a specific thing actually costs now versus then. Eggs went from $X to $Y. Gas went from $X to $Y. This site is mostly about #4.

A given news story can say "inflation is high" using #1 while "inflation is cooling" using #3, while a politician simultaneously waves around #4 and says "look at what eggs cost." None of them are lying. They're talking about different things.

What "inflation is X%" actually means

When you see "CPI rose 3.0% year-over-year", that does not mean every single thing got 3% more expensive. It's a weighted average of about 80,000 specific prices, where each item is weighted by how much typical households actually spend on it.

What this means in practice:

• Housing is roughly a third of the index. Rent and "owners' equivalent rent" alone account for ~33% of CPI. If rent inflation flattens, headline inflation flattens, even if other things keep climbing.
• Food is about 13%, energy about 7%. This is why "core" (which excludes them) is sometimes a better read on underlying trend.
• Eggs are about 0.1% of the index. A 50% spike in egg prices, by itself, doesn't move CPI much. Which is exactly why the vibes mismatch with the number on egg-spike weeks: people experience the shopping cart, not the index weights.

The four cheap tricks to watch for

When someone uses a number to make an argument, check these:

1. Cherry-picked start date. "Gas is up 90% since 2020!" — technically true, because gas was historically cheap during COVID lockdowns when nobody was driving. Picking April 2020 as the baseline is like picking the bottom of a trough. Always ask: why this start date?

2. Cherry-picked endpoint. "Egg prices have come down 40% from their peak!" — also true, but the peak was an HPAI-driven spike. Coming down from a crisis isn't the same as being affordable.

3. Year-over-year vs cumulative. "Inflation is back to 2%." — that means prices are still rising, just slowly. The total price level is up roughly 22% since early 2020. "Back to 2%" doesn't mean prices came down. Inflation = the speed of price increase, not the price itself.

4. The wrong index for the question. The CPI is consumer prices. The PPI (Producer Price Index) is wholesale. The PCE (Personal Consumption Expenditures) is what the Federal Reserve actually watches. Most arguments about Fed policy should use PCE, not CPI, and they often don't.

How to read this site honestly

A few things we try to do, and how we'd like you to push back on us if we're sloppy:

• We anchor to January 2019 for percent-change comparisons. It's pre-COVID, post the 2018 trade-war volatility, and stable. It's an opinionated choice. If you have a better one, tell us.
• We show prices, not inflation rates. A line going from $2.99 to $4.99 is more useful than "+67%" floating in a headline. Both are on every page.
• We mark estimates explicitly. Some BLS series don't publish state-level data; we sometimes apply regional-parity adjustments to estimate state prices. When we do that, we say so on the chart.
• We try not to imply causation we can't prove. "Carpooling won't lower national gas prices" is a thing we'll keep repeating, because the household savings are real even though the macro impact isn't.

If you read inflation coverage with these checks in mind, most of it gets a lot less confusing. The headline number is real, but it's a summary. Your grocery cart is also real, and it's not a summary.

Both are true. Both are useful. Don't let anyone make you pick one.

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This is the kind of post we'll update over time. If you spot something here that's stale or wrong, let us know.