CORI/RISI Ontology
US Census
The US census have multiple data survey and data product.
The main one are:
The decennial census
ACS five and one year
The Economic Census
Census of Governments
US census developper section:
The US census has resources for developpers: https://www.census.gov/data/developers.html
Decennial data only go back to 2000 but historical data are also provided by IPUMS NHGIS.
IPUMS has an R package wrappintg their API: https://tech.popdata.org/ipumsr/index.html
The American Community Survey (ACS) …
- is an ongoing initiative within the United States Census Bureau
- releases a variety of data tables every year covering a wide range of social, economic, housing, and demographic data
- ACS has two types of data “profile” and “table”
A Block …
- is the smallest geographic area for which the Bureau of the Census collects and tabulates decennial census data
- is the smallest statistical unit of analysis of a single Community’s economic participation, social impact, and inventory of tech ecosystem resources (?)
- is the smallest geospatial unit at which we can geographically place, filter or group Broadband Serviceable Location data
- is a collection of Broadband Serviceable Location(s)
- can not be statistically described by data that is attributed to the block group, tract census boundaries that forming the set of blocks to which it belongs
- may be a constituent component of one and only one block group
- is a constituent component of one and only one tract
A Block Group …
- is …
A Tract …
- Started being used in 1910 (NY city), at first should follow rivers and roads and contains around 400 peoples.
- if divided between two new tracts and should follow this kind of pattern1
1 Census Tract O3 (parent) is divided in Census Tract 03.01 (child 1) and Census Tract 03.02. https://www.youtube.com/watch?v=DOe4alPmjss
Note Olivier 26-04-2024: still unclear how that translate in geoid_tr and how do they deal when we move from two “parents” to one “child”
- is a union of the set of blocks and/or block groups that are located within a specified geographical boundary (unsure about that do they start from block and build tract or tract and divide in block)
- is often arbitrary, except for coinciding with political lines, in unincorporated areas of the United States
- for some metrics, can be statistically described by the aggregation of statistics for each of its constituent blocks
A Rural Tract …
- is …
An Unincorporated Area …
- is a region that is not governed by a local municipality, see also Census Designated Space (CDP)2
2 https://www.census.gov/programs-surveys/bas/information/cdp.html
A County …
- is …
A Rural County …
- is …
A CUD …
- is …
A ZIP (“Zone Improvement Plan”) code / ZCTA …
- is a designation for a mail delivery route, they usually follow roads that ware assigned to a postman.
- is, at the smallest level, tied to an address (point).
- can be linked to a census tabulation blocks by Zip Code Tabulation Areas (ZCTA) provided by the Census Bureau.3
3 https://www.census.gov/programs-surveys/geography/guidance/geo-areas/zctas.html