Inflation is a sustained increase in the general price level of goods and services. It does not mean every price rises at the same rate, and it is different from the price level itself. If inflation slows from 6% to 3%, prices are still increasing overall; they are simply rising more slowly. That slowdown is called disinflation. Deflation, by contrast, means the overall price level is falling.
In the United States, the most familiar measure is the Consumer Price Index. The latest available CPI before the September 11, 2026 release is July 2026: the U.S. Bureau of Labor Statistics — Consumer Price Index, July 2026 reported that CPI-U rose 0.1% in July and 3.4% over the previous twelve months. Core CPI, which excludes food and energy, rose 2.5% over the year. These figures show why current inflation discussions should use dated releases rather than old examples.
CPI, PCE, and the GDP Deflator Measure Inflation Differently
The CPI tracks prices paid by urban consumers for a defined basket of goods and services. The BLS — Consumer Price Index Frequently Asked Questions explains how the index is constructed and why individual households can experience different inflation. People who spend more than average on rent, healthcare, food, or transport may feel a very different cost increase from the national headline number.
The Bureau of Economic Analysis — PCE Price Index covers a broader range of consumer spending and adjusts differently as consumer behavior changes. In July 2026, the PCE price index was up 3.7% from a year earlier. The Federal Reserve pays particular attention to PCE inflation, while analysts may also use the BEA — GDP Price Deflator for prices across domestically produced goods and services.
Inflation Can Come From Demand, Costs, Supply Shocks, and Expectations
Demand-pull inflation occurs when total spending grows faster than the economy’s ability to supply goods and services. Cost-push inflation occurs when inputs such as energy, labor, transport, or materials become more expensive and businesses pass part of those costs to buyers. Supply shocks, including crop failures, wars, shipping disruption, or shortages of key components, can raise selected prices rapidly.
Monetary and financial conditions also affect demand over time. Low borrowing costs and strong credit growth can support spending and investment, while higher interest rates tend to slow borrowing and demand. Expectations matter because businesses and workers make decisions partly based on what they think future prices and wages will do.
Inflation Affects Purchasing Power Unevenly
If income rises more slowly than prices, real purchasing power falls. This can reduce a household’s standard of living, especially when necessities account for a large share of the budget. People holding cash or low-interest balances can also lose real value when inflation exceeds the return on a savings account.
Unexpected inflation can benefit some borrowers because fixed debts are repaid with dollars that have less purchasing power, while lenders may lose if interest rates did not anticipate the inflation. Businesses face another problem: rapid price changes make it harder to plan wages, inventory, contracts, and long-term capital expenditure and investment analysis.
Central Banks Try to Reduce Inflation Without Creating Excessive Economic Damage
The Federal Reserve influences inflation primarily through monetary policy rather than controlling individual prices. Higher policy rates tend to restrain credit, asset demand, consumption, and investment, but those effects occur with delays. The Federal Reserve — Longer-Run Goals and Monetary Policy Strategy and Federal Reserve — July 2026 Monetary Policy Report provide current policy context.
The Fed’s longer-run inflation objective is 2%, measured by the PCE price index. Very high inflation erodes purchasing power and creates uncertainty, but inflation that is persistently too low can also be problematic because it reduces room for interest-rate cuts and can increase the real burden of debt. Price stability is therefore about keeping inflation low and predictable rather than forcing every price to remain unchanged.
Conclusion
Inflation is the rate at which the overall price level rises, and it should be distinguished from disinflation, deflation, and changes in individual prices. CPI, PCE, and the GDP deflator measure different parts of the economy, so analysts use them for different purposes. As of the latest July 2026 data, U.S. CPI inflation was 3.4% year over year and PCE inflation was 3.7%. The causes can include demand, costs, supply shocks, monetary conditions, and expectations, while the effects vary across households, businesses, savers, borrowers, and investors.