topic Re: Population Weighted Centroids from Census Block Groups in Spatial Statistics Questions

Population Weighted Centroids from Census Block Groups

SamanthaStieger — Sun, 31 Mar 2013 22:21:14 GMT

Hi -- I am trying to make population weighted centroids from census block groups. Downloaded some data from the Census Bureau to get block groups for California but theres no population in the table. So I downloaded another table that had population at the Census Block group level and joined the two. Not sure if that was right. Then I used feature to point to make centroids. Is this the best way to achieve this? Any help would be greatly appreciated! Thanks!

Re: Population Weighted Centroids from Census Block Groups

PhilMorefield — Wed, 26 Jun 2013 18:23:19 GMT

For future reference, Census provides population center shapefiles for many levels of gegraphy:

http://www.census.gov/geo/reference/centersofpop.html

Re: Population Weighted Centroids from Census Block Groups

ArvindBambhroliya — Fri, 16 Oct 2015 17:38:59 GMT

Thanks Phil for pointing to this link. I have a follow-up question on this.

Is mean centers of population considered as the population-weighted centroids as many authors described in the methods section (for example, JAMA Network | JAMA Neurology | ACCESS: Acute Cerebrovascular Care in Emergency Stroke Systems ) ?

Thanks.

Arvind

Re: Population Weighted Centroids from Census Block Groups

DanPatterson_Retired — Fri, 16 Oct 2015 20:10:39 GMT

You will have to read it further

to quote

Population information was obtained using data from the US Census Bureau and deliverable addresses from the US Postal Service (Claritus Inc, Ithaca, NY).37,38 Our main geographic units of analysis were block groups. A block group is a geographic unit containing 600 to 3000 people that does not cross state or county boundaries. Each block group's population was assigned a point in space (a centroid) that was nearest to most residents. Population estimates and population-weighted centroids for 208 667 block groups were calculated for 2007 for the entire United States.

Re: Population Weighted Centroids from Census Block Groups

ArvindBambhroliya — Fri, 16 Oct 2015 20:22:14 GMT

Thanks for the reply and quoting the text. So, are population-weighted centroids (described in the paper) similar to mean centers of populations (available at http://www.census.gov/geo/reference/centersofpop.html)?

Another question: Can population-weighted centroids for 'block groups' be calculated from the population estimates of 'block groups'? OR Calculations of population-weighted centroids for 'block groups' need population estimates of 'BLOCKS' instead of 'BLOCK GROUPS'?