DEFINITION
Undercount, Undercount Rate, City Undercount Share
The decennial census attempts to count all persons, but always misses some people.
The 1990 undercount is the number of persons estimated by the Census Bureau to have been
missed (not counted) in the 1990 census enumeration. These figures were estimated using a
sample survey several months after the census enumeration on April 1. The sum of
the undercount and the official census population count is the statistically
adjusted population estimate.
Note that an undercount with a minus sign denotes an overcount. The term
"undercount" in this report refers to the net undercount.
The undercount rate is the undercount as a percent of the adjusted population. It represents the percent of the population that was missed in the census enumeration.
The differential undercount refers to the difference between the undercount rate of minority groups and the rate of non-Hispanic Whites. The overall or total undercount refers to the undercount of all groups.
An undercount share is the undercount in a local area as a percent of the total undercount in a larger region. For example, city undercounts can be calculated as a share of the total county undercount.
Undercount + Official Census Population = Adjusted Population
Example: California, 1990
| 1990 Official Census Population 1990 Undercount 1990 Adjusted Population |
29,760,021 persons counted on April 1 + 837,557 persons undercounted 30,597,578 persons |
Undercount Rate = (Undercount / Adjusted Population) X 100
|
1990 Undercount
X 100 = 1990 Adjusted Population |
1990 Undercount
X 100 1990 Undercount + 1990 Official Census Population |
Example: California, 1990
| = 837,557 X
100 30,597,578 |
= 2.74% |
City Undercount Share = The city undercount as a percentage of the total county undercount
Example: Oakland City, Alameda County, 1990
1990 Undercount Oakland City X 100 =
1990 Undercount Alameda County19,316 X 100 = 50.7
38,080