County Size (cntysc)
Counties are categorized by nine population interval categories. Even though we use the original name from the geographic headers portions of the census summary files where it is stored as a code, the values stored in MABLE are just character strings indicating the interval. The values are:
- Less than 200
Place Size (placesc)
Same idea as cntysc but this is for place size rather than county. Values are the same as for cntysc:
Based on census 2000 place boundary definitions and populations.
- Not in a place
- Less than 200
Within a Place
This is a category variable that allows you to look at a breakout of an area based on how much of it is inside or outside of a place, with detail as to whether the place is incorporated or a Census Designated Place (CDP). The 1-character code values are
Based on census 2010 place boundary definitions.
- 1=Within an incorporated place
- 2=Within a CDP
- 3=Not in a place
Census Place code
The Census Bureau has their own set of 4-digit place codes that were used before they switched to 5-digit FIPS codes some time between the 1980 and 1990 censuses. This field is blank for places that did not exist in 1980. Only useful for capturing codes that you plan to use in conjunction with earlier census data (1980 or earlier). Normally you will use the regular Place geocode, which is the FIPS version.
Census County Subdivision code
This does for county subdivisions what the previous entry does for places. These are 3-digit codes that the Census Bureau assigned and used in their products before switching to the more standard FIPS codes. These codes are only unique within county. They have leading zeroes and usually appear in increments of 5. So most counties have CenCouSub codes of 005, 010, 015, etc.
Transportation Analysis Zone (TAZ)
These areas are used by the transportation planning community to do things like setting up work trip matrices that count commuting flows between these zones. These are important geographic units on special products like the various Census Transportation Planning Packages (CTTP) that the Census Bureau creates based on specs from the U.S. Department of Transportation. Coding schemes vary from state to state and metro area to metro area. They can be up to 6 characters long. A value of 999999 indicates an area where no TAZ has been defined. They appear to be unique within county (but you have to select County explicitly when selecting TAZ as a Source or Target code.) There are no names associated with these codes. We have not yet (as of December, 2013) added these values to MABLE for 2012.
For additional background information on any of the geographic units
maintained or utilized by the Census Bureau you can view the
Geographic Areas Reference
Manual which is now available on the Geography Divsion's
Other useful links: