What is the relationship between price indices above and below 100?

A price index is a measure that examines the weighted average of prices of a basket of consumer goods and services, typically used to assess price changes over time. When a price index is above 100, it indicates that the prices have risen compared to the base period (which is represented by an index of 100). Conversely, an index below 100 signals that prices have fallen relative to that base period.

Therefore, the correct understanding of the relationship is that indices above 100 represent an increase in price levels, while those below 100 indicate a decrease. This interpretation is fundamental in economic analysis, as it helps businesses, policymakers, and economists to gauge economic conditions, inflationary trends, and the purchasing power of consumers.

In this context, the other options do not accurately reflect the meaning of price indices. Indices being stable or having no significance contradict the basic premise of what indices represent regarding price movements and the economic situation.