Los Angeles Family and Neighborhood Survey (L.A.FANS): Neighborhood Characteristics
QUESTION: I requested and received the public LAFANS data in order to investigate the influence of neighborhood characteristics on English language acquisition amongst immigrant households in the LA area. Am I correct that the public data contain the household survey, but no neighborhood survey, no survey of neighborhood characteristics, and no information about the neighborhoods in which the households in the household survey live?
RESPONSE:
Chapter 4 of the LAFANS main codebook describes how the occupation codes were created. They are based on the codes used in 1990 Census of Population and Housing. The footnote citing the source of the occupation codes says: “CPH-R-4, 1990 Census of Population and Housing: Classified Index of Industries and Occupations: 1990. This document is a companion to the Alphabetical Index (CPH-R-3). Industry and occupation titles are arranged by classification code. It presents for each category in the industrial and occupational classification systems the individual titles that constitute the category.”
The following website provides crosswalks among industry and occupation codes used by the Bureau of the Census. There are occupation and industry crosswalks for comparing data from the 1990 Census to the 2000 Census: Industry and Occupation Code Lists & Crosswalks
The 2-digit codes in the LAFANS represent combinations of 3-digit 1990 Census occupation codes and are not just the 1st two digits. There is a crosswalk table (Table A.1) in Appendix A of the LAFANS main codebook that shows which 3-digit codes are used to create each 2-digit code. Appendix A shows what the 3-digit codes represent. Table 4.4 in the LAFANS Main codebook shows what the 2-digit codes represent. All of this is discussed in Chapter 4 of the LAFANS main codebook.
QUESTION: I am merging information from the 2000 census to the 65 neighborhoods in the LAFANS sampling frame. I compared maps of the 65 tracts in the 1990 census to the 90 tracts that appear in the 2000 census and confirmed that the most common reason for the increase in tracts between the two censuses was that they had been split (although there were some exceptions). How do I get information from the 2000 census for the original 65 tracts as sampled from the 1990 census (and not the 90 tracts that now appear in the 2000 census)?
RESPONSE:
There are a lot of different methods used by geographers to deal with this problem, including taking weighted averages and more sophisticated approaches. I suggest that you get in touch with a GIS person or geographer at your institution for some advice on how to handle this (although, of course, given that you are working with confidential data, you cannot give the geographer or GIS person the numbers of the tracts within L.A.FANS without getting permission from RAND — unless the person works for you and signs a Supplementary Agreement).
Another option is to look at the 1990-2000 Census tract relationship and block relationship files available online from the US Census Bureau. These contain proportions to use in converting 2000 tract data back to 1990 tracts:
Another source for this information is the L.A. Neighborhood Services and Characteristics database (L.A.NSC) that is available on the L.A.FANS website. This database provides a cross-walk from 2000 tracts into 1990 tracts for all tracts in Los Angeles which is based on the Census files mentioned above. The L.A.NSC also provides detailed information from the censuses and other sources for all Los Angeles census tracts.