The following charts represent the number of net migrants by age group by county or region of Colorado for the time periods 1995-2000, 2000-2010, and our current forecast for 2010-2020. Net migration is the sum of in-migrants minus the number of out-migrants by age group.

Net migration for 1995-2000 was determined from Census questionnaires by region and county. Net migration for the years 2000-2010 was determined from a demographic analysis of population from difference of the population by age from the U.S. Bureau of the Census for the years 2000 and 2010, adding births as reported by the Colorado Department of Public Health and Environment (CDPHE) and subtracting deaths by single year of age for the intercensal years as reported by CDPHE. Net migration for the years 2010-2020 was extracted from the current Colorado population projection model.

Colorado’s current population projection model assumes an in-migration amount for three types of in-migrants distributed by a region-specific age-sex distributions dependent on the type of in-migrant. In-migrants are assumed to relocate to Colorado for a job, for an amenity (mainly retirees), or for a specific institution (college, prison, ski resort workers, and military personnel). The in-migration amounts of persons assumed to relocate to Colorado for employment and their family members are determined exogenously using an economic-demographic forecast model which determines the number of expected jobs in a county relative to the labor force available for the jobs. In-migration amounts for retirees are determined through a trend analysis of historical data on the number of migrants to Colorado. In-migration amounts of special populations are determined using information from local, state, and federal government agencies on expansion or contraction of specific facilities. Each type of in-migrant is then distributed to a region through a region and age-sex distribution.

The current model uses region age-sex specific out-migration rates developed from historical data on out-movers from Colorado to other regions within Colorado as well as movement out side of Colorado to the rest of the United States from questionnaires from the U.S. Bureau of the Census and the Current Population Survey to determine the number of out-migrants. The number of out-migrants is dependent on the current and forecast age-sex structure of Colorado’s population as the out-migration rates are held constant by age-sex group over the forecast horizon, but the population subject to the rates changes annually.

The following page shows comparison charts for the net migration by age data set. The chart on the left includes totals of net migrants by age group. The chart on the bottom is the net migration rate by age. . Select the county from the list above to view the graphs for that county. All graphs are interactive and you are able to zoom in and out on any area of each graph by drawing boxes around the area you would to view with your mouse. To zoom back out, simply double click on any area of the graph. You can also hover over specific data points on each graph to view the data for that specific point.