What is the term for the annual percentage rate of change in price level as reflected by price indexes?

The term that refers to the annual percentage rate of change in price level, as reflected by price indexes, is the inflation rate. Inflation represents the general increase in prices and the corresponding decrease in the purchasing power of money over time. This rate is typically calculated using price indexes such as the Consumer Price Index (CPI), which measures changes in the price level of a basket of consumer goods and services.

Understanding the inflation rate is crucial for analyzing economic conditions, making investment decisions, and assessing the effectiveness of monetary policy. It is a key indicator that economists and policymakers use to gauge the health of an economy. While the Consumer Price Index itself is a tool used to measure inflation, the inflation rate specifically quantifies how rapidly prices are increasing over a specified period, usually expressed on an annual basis.