What is an annual rate? Why are seasonally adjusted data often shown as annual rates?
Very generally, what we call the seasonally adjusted annual rate for an individual month (quarter) is an estimate of what the annual total would be if non-seasonal conditions were the same all year. This “rate” is not a rate in a technical sense but is a level estimate. The seasonally adjusted annual rate is the seasonally adjusted monthly value multiplied by 12 (4 for quarterly series). For example, The benefit of the annual rate is that we can compare one month’s data or one quarter’s data to an annual total, and we can compare a month to a quarter. The Bureau of Economic Analysis (BEA) publishes quarterly estimates of the United States gross domestic product (GDP) at an annual rate, and many of the Census Bureau data series are inputs to GDP. Annual rates for input series help users see the data at the same level as GDP estimates.
