Which economic indicator measures the average prices of products and services over time?

The Consumer Price Index (CPI) is the correct answer because it specifically tracks the average price change of a basket of goods and services over time. This index is widely used to assess inflationary trends, as it reflects how the costs of living change for consumers. By measuring the average price levels, the CPI provides valuable insights into purchasing power, cost of living adjustments, and overall economic health.

It's important to note that other economic indicators mentioned do not focus specifically on average price changes. For instance, Gross Domestic Product (GDP) measures the total economic output of a country and does not directly indicate price changes or inflation levels. The Employment Rate Index tracks employment trends in the labor market, while the Inflation Rate itself is more of a derivative measure that uses CPI data to quantify the rate at which prices are rising, but does not directly monitor price levels over time the way CPI does.