Inflation Explained

A closer look at what causes inflation and how it's actually measured across an economy.

The money basics module introduced inflation as prices simply rising over time. This lesson goes one meaningful level deeper: how inflation is actually measured across an entire economy, and the two broad, genuinely distinct forces that typically cause it in the first place.

How inflation is actually measured

The CPI, or Consumer Price Index, tracks the average price of a broad basket of goods and services that a typical household regularly buys - groceries, rent, transportation, healthcare - over time. The percentage change in the CPI from one year to the next is the headline inflation rate you’ll see reported in the news. It’s an average across an entire representative basket, which means your own personal experience of inflation can genuinely differ if your own spending pattern looks meaningfully different from that standard basket - someone spending heavily on housing, for instance, feels housing-driven inflation more acutely than the general headline number alone might suggest.

Demand-pull inflation

Demand-pull inflation happens when overall demand for goods and services grows faster than the economy’s genuine ability to supply them. If suddenly far more people want to buy homes than there are homes actually available, prices naturally get bid upward - too much money chasing too few available goods, as the classic economic description puts it plainly.

Demand-pull inflation in a single market

Imagine a popular concert venue with exactly 5,000 seats, and 50,000 people trying to buy tickets the moment they go on sale. Even at a fixed original price, resale prices tend to shoot upward almost immediately, purely because far more people want tickets than there are seats to sell. This same basic mechanism, playing out across an entire economy's worth of goods and services at once rather than just one concert, is essentially what demand-pull inflation looks like at scale.

Cost-push inflation

Cost-push inflation happens from the opposite direction entirely: the cost of actually producing goods rises - more expensive raw materials, higher wages, disrupted supply chains - and businesses pass at least some of that increased cost directly on to consumers through higher prices. A spike in oil prices, for instance, raises transportation costs across nearly the entire economy at once, showing up as higher prices well beyond just fuel itself, since almost everything physical needs to be transported somewhere along its journey to a customer.

The mistake that comes from treating all inflation the same

Assuming every inflation headline has the same cause and cure

The exact same headline inflation rate can genuinely come from very different underlying causes, and the appropriate policy response often differs considerably depending on which one is actually driving it - a distinction the next lesson, on interest rates and the central bank, picks up directly. Treating every inflation headline as identical, with the same obvious cause and the same obvious fix, misses the fact that demand-pull and cost-push inflation often call for meaningfully different responses.

Why recognizing the type actually matters

Recognizing which type of inflation a specific news report is describing is a genuinely useful skill for understanding not just that something is happening, but why - and, by extension, what kind of policy response might reasonably be expected to follow, which is exactly what the following lesson on central banks and interest rates explores in detail.

Key takeaways

The CPI tracks average prices across a broad basket of goods - your personal experience can differ from the average.
Demand-pull inflation happens when demand outpaces the economy's ability to supply goods and services.
Cost-push inflation happens when rising production costs get passed on to consumers as higher prices.
The same headline inflation number can come from genuinely different causes, calling for different responses.
Recognizing which type is driving a headline helps predict what kind of policy response might follow.