Several variables in the main data set provide information about the respondent’s area of residence. These variables permit researchers to identify key characteristics of the area without needing access to the geocode CD-ROM. Geographic variables were created using a software program called Maptitude, V4.2; therefore, no programming code is provided for these variables. Instead, this document offers a brief general description of the methods used to generate these variables. For more information about the process of classifying a respondent’s metropolitan area or about the geographic variables in general, refer to the introduction to the Geocode Codebook Supplement or contact NLS User Services.
| User Notes: Researchers should be aware that the process for geocoding respondent residences has been changed since the initial survey round. All residence information was re-geocoded using the new, more accurate approach, so all variables are comparable across rounds. However, researchers should not use geographic variables from old data sets in analyses; all geographic data should be taken from the newest release. |
Variable Created: CV_CENSUS_REGION
This variable classifies respondents as residing in one of four regions defined by the U.S. Bureau of the Census. These regions are as follows:
|
Census Division |
States |
|
Northeast |
Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont |
|
North Central |
Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin |
|
South |
Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia |
|
West |
Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming |
Variable Created: CV_MSA
This variable provides users with information about whether the respondent lived in the central city of the MSA, in another part of the MSA, or outside of an MSA. As defined by the Census Bureau, a central city is the major city lying within a Metropolitan Statistical Area (MSA). Initially, a variable was created using the TIGER/Line files (a database developed by the Census Bureau; the round 5 variable used the 1998 version) to determine whether the respondent lived in an MSA. A second variable was created based on “places” data in the Maptitude program that identified whether the respondent lived in the central city. The version of Maptitude used for round 5 used the 1992 TIGER/Line files to classify places as central cities. The variables were then combined to produce a single MSA/central city variable. For this dataset, respondents are coded as follows:
not in MSA
in MSA, not central city
in MSA, central city
in MSA, not known
not in country
Variable Created: CV_URBAN_RURAL
Places are identified as urban or rural by the Census Bureau. Urban places are those in “urbanized areas” or “places” with a population of at least 2,500; all other areas are rural. According to the Census Bureau, about 25 percent of the U.S. population lives in rural areas. The “urbanized area” map in the Maptitude software used in round 5 was derived from the 1990 Census Bureau TIGER/Line files. Respondents residing in urban areas are coded 1 and those residing in rural areas are coded 0. Census Bureau information on urban and rural places can be retrieved from the following internet site: http://www.census.gov/geo/www/tiger/index.html.
Users should note that this variable includes an “unknown” category. This value is assigned to respondents whose zip code includes both urban and rural areas or whose residence cannot be identified precisely enough to classify it as urban or rural. Respondents without valid address data are assigned a value of –3, invalid skip. Respondents who live out of the country are assigned a value of –4, valid skip.
Variable Created: CV_MIGRATE.xx
To provide information about the respondent's migration history, survey staff create this variable based on state and county codes as assigned by the geocoding program. The variable released to public users classifies respondent moves into one of the following four categories:
Respondents who have not moved since the previous interview are assigned a value of -4, valid skip. If respondent address information is incomplete and survey staff are unable to determine locations of the respondent's residences, the respondent is assigned a value of -3, invalid skip.