Columbia, MD - Oct 10, 2001 - Arbitron released its annual update of population estimates for its 285 radio markets across the United States. This update covers total, black and Hispanic populations for persons age 12 and older and will be used for the Fall 2001 survey.
The estimates for total populations are based on Census 2000 data, updated and projected to January 1, 2002. Because appropriately detailed age/sex data from Census 2000 was not available in time for the updates, estimates for age/sex demographics within the total population will continue to be based on 1990 Census data, updated and projected to January 1, 2002. Late in the fourth quarter, Arbitron will update age/sex demographic estimates for use with the Winter and Spring 2002 surveys.
Unusual changes between the Fall 2001 and Fall 2000 population estimates for a particular market can be attributed to the recalibration to the new Census 2000 data. Such changes should not be interpreted as a one-year increase or decrease in the actual population; they are technical changes rather than actual changes. These technical changes mean that the new, 2000-based estimates should provide a better picture of the population than last year's 1990-based estimates.
The impact of the Fall 2001 population estimates update on individual markets can viewed using the Market-Specific Comparison application, located on the Arbitron website at www.arbitron.com/radio_stations/census.htm. Fall 2001 market ranks for total persons 12+, as well as black and Hispanic populations, are also available on the Arbitron website.
How Arbitron Market Population Estimates Are Compiled
Each year, Market Statistics, a division of Claritas, Inc., produces updated population estimates that are usually used in Arbitron's surveys for the next 12 months. These estimates start with the most recent decennial census and are updated using a variety of local, state and federal data.
Census 2000 age and sex demographics were not available in time to use for the current estimates. For age and sex demographics for the Fall survey, Market Statistics used 1990 Census population data, which have been continually updated using a variety of local, state and federal information.
Late in the fourth quarter, Market Statistics will release an additional set of population estimates using the age and sex demographic details from Census 2000. This second set of estimates will be used by Arbitron for the Winter 2002 survey in continuous-measurement markets and the Spring 2002 survey in all other markets.