Not ready for prime time: zip codes and census tracts. Using census tract data from census 2000 July 2010

Transcription

1 Not ready for prime time: zip codes and census tracts. Using census tract data from census 2000 July 2010 One of the more compelling reasons to use summary level data is to get tabulations at small levels of geography, such as census tracts or zip codes. Neither of these geographies are available from the American Community Survey yet. However, we can walk through examples using the 2000 Census. Go to the portal for accessing data from American Factfinder: Click on get data for the Decennial Census choice: There are several choices of data: Summary File 1 4. Summary Files 1 and 2 have information for the 100% data (age, sex, race, Hispanic/Latino origin, household relationship, whether residence is owned or rented). This is exactly what was asked in the 2010 Census. While this is rather thin content, one can get a surprising amount of information using these demographic indicators. For instance, in the 2008 primaries, age, sex, and race predicted quite a bit of the Clinton/Obama divide.

2 The more popular tabulations come from Summary Files 3 and 4, which include all the sample items (income, education, marital status, occupation, ancestry, etc.). This is what is what the ACS is now collecting. The even numbered summary files (2 and 4) iterate the tables across all the race choices. While these are useful if you are interested in a table for the Mexican population or the Black/Asian population, the examples we will examine will be for the total population. As a note, many of the race specific tables end up with no data for some geographies as there are many census tracts with no Black/Asians or too few Mexicans. This example will allow one to look at vacancy status across census tracts in Cleveland, OH. The overall vacancy rate in the Cleveland PMSA in 2008 is 11.5 percent, but it is likely that there is a great deal of variation by census tract. Starting in 2010, researchers will be able to get census tract data on an annual basis. Move the marker to circle labeled Census 2000 Summary File 3 (SF 3) Sample Data For this example, select Detailed Table This takes you to a series of choices of your geographic unit: Change the selection method from list to geo within geo Select Census Tracts under Show me all Select Primary Metropolitan Statistical Area The interface will give you a choice of Fully or partially contained within the Primary Metropolitan Statistical Area Leave the default (fully or partially) Select Cleveland Akron, OH CMSA under Select a metropolitan statistical area Select Cleveland Lorain Elyria, OH PMSA under Select a primary metropolitan area

3 Select All Census Tracts under Select one or more geographic areas Click Add Click Next This takes you to the Table Selection interface Again, until one is familiar with the table choices, one is best off looking at the tables by subject: Choose by subject as the Table Selection method Highlight Occupancy and Vacancy Status under Housing Characteristics Click on Search Highlight H.6 Occupancy Status Click Add Click Show Result Go to the Print/Download area near the top of the Results page Slide to Download Select Comma delimited under the Database choices Click on OK Save the zip file to the desktop with a name that makes sense, e.g., Vacancy2000_Cleveland_censustracts.zip Click on zip file Extract the last file (dt_dec_2000_sf3_u_data1.txt) and save it as a text file, e.g., Vacancy2000_Cleveland.txt. Then use Excel to import the data. If you save the file with a csv extension, you can click on it and Excel will recognize it. However, that prevents you from identifying certain fields as text, which is relevant for mapping. Below is a file I created, which you can manipulate:

4 There are 6 census tracts in the Cleveland metro area with vacancy rates of 40 percent or more and another 12 that range between 25 and 39 percent. All but one of these are in Cuyahoga county: Census Tract 1073, Cuyahoga County, Ohio 56.76% Census Tract 1131, Cuyahoga County, Ohio 47.48% Census Tract 1076, Cuyahoga County, Ohio 47.17% Census Tract 1144, Cuyahoga County, Ohio 46.63% Census Tract 1189, Cuyahoga County, Ohio 43.63% Census Tract 1037, Cuyahoga County, Ohio 43.35% Census Tract 1071, Cuyahoga County, Ohio 38.45% Census Tract 1078, Cuyahoga County, Ohio 33.17% Census Tract 1138, Cuyahoga County, Ohio 30.24% Census Tract 1514, Cuyahoga County, Ohio 29.17% Census Tract 1097, Cuyahoga County, Ohio 28.20% Census Tract 1143, Cuyahoga County, Ohio 27.52% Census Tract 1133, Cuyahoga County, Ohio 27.05% Census Tract 1123, Cuyahoga County, Ohio 26.67% Census Tract 1148, Cuyahoga County, Ohio 26.30% Census Tract 1042, Cuyahoga County, Ohio 25.93% Census Tract 1082, Cuyahoga County, Ohio 25.48% Census Tract , Lorain County, Ohio 25.26% On the other end of the spectrum, over 400 of the census tracts in the metropolitan area have vacancy rates below 5 percent. Here s a map of the 2000 vacancy rates using data from Census 2000:

5 Starting in 2010, we will be able to map communities at a detailed level, on an annual basis. One last note about vacancies, which is relevant to the American Community Survey. Recall that the ACS data are collected year round. This means that in areas of the country where there is seasonal housing, the vacancy rates may fall and/or the proportion of vacant houses that are seasonal houses may fall. This is because the seasonal residences are being lived in during some of the sample time period. Here s a map of vacancy rates for counties based on the 2000 Census.