What causes inflation?

Inflation happens when prices across an economy keep rising, so the same money buys less than before. Its three primary causes are demand-pull inflation, where spending grows faster than supply; cost-push inflation, where businesses face higher costs and pass some of them on; and built-in inflation, where people expect future price rises and act in ways that help make them happen. These causes often overlap, so one shock can spread through wages, prices, demand, and expectations.

Demand-pull inflation

Demand-pull inflation starts with buyers. If households, businesses, governments, or overseas customers want more goods and services than the economy can comfortably produce, sellers can raise prices because demand is strong.

The key point is capacity. An economy can absorb extra spending if shops, factories, farms, transport networks, and workers can increase output to match it. If they cannot, the extra demand runs into bottlenecks. Prices then do some of the rationing: people who are willing or able to pay more get served first.

This type of inflation is most likely when employment is strong, credit is easy, confidence is high, or public spending rises quickly. It does not mean every seller raises prices for the same reason. It means the balance of the whole economy has shifted towards more spending than available supply.

Cost-push inflation

Cost-push inflation begins with the cost of making or delivering things. If energy, food inputs, raw materials, rent, shipping, or labour become more expensive, businesses may raise prices to cover part of the increase.

This can happen even when demand is not especially strong. A bakery that pays more for flour and electricity faces a real cost increase whether customers feel richer or poorer. If many businesses face similar pressure at once, the result can be a broad rise in prices.

Cost-push inflation is difficult because the first cause is often a supply problem, not excess spending. Higher interest rates may reduce demand, but they do not directly create more fuel, crops, housing, or transport capacity. That is why a cost shock can feel different from an overheated boom: prices rise while households and firms may already feel squeezed.

Built-in inflation and expectations

Built-in inflation is the part that comes from behaviour adjusting to expected inflation. If workers expect prices to keep rising, they may ask for higher pay to protect their living standards. If businesses expect wages, rent, materials, or financing costs to rise, they may lift prices in advance. Those decisions can then make the expected inflation more real.

This is how expectations of future inflation can become self-fulfilling. People are not imagining the problem; they are trying to protect themselves from it. But when many people and firms act that way at the same time, wage and price decisions start to carry yesterday’s inflation into tomorrow.

Built-in inflation is sometimes described as a wage-price spiral, but wages are not the only channel. Long-term contracts, rent reviews, supplier agreements, and price-setting habits can all carry expectations into current prices.

How the causes reinforce each other

Inflation rarely has one clean cause. Strong demand can make it easier for firms to pass on higher costs. A supply shock can raise prices, which can lead workers and businesses to expect further rises. Those expectations can then build inflation into future wage deals and pricing decisions.

Understanding the main driver matters because different causes call for different responses. Cooling demand is not the same problem as repairing supply, and anchoring expectations is not the same as lowering one input cost. The useful question is not only “what started inflation?” but “what is keeping it going?”