The base period is a fixed point in time used as a benchmark to measure and compare statistical data, such as indices, over a subsequent span of time. This concept is often employed to assess changes in economic indicators like the Consumer Price Index (CPI).
A Metropolitan Statistical Area (MSA) includes one or more counties with a central urban area having a population of at least 50,000 inhabitants. The U.S. Census Bureau uses MSAs for the purposes of aggregating and reporting population, housing, and economic statistics.
