Daily Archives: November 9, 2013

100 Largest School Districts

Based on enrollment as of the 2012-13 school year, the 100 largest school districts ranged from enrollment of 45,705 (Shelby County, TN) to 993,903 (New York City Public Schools). Use the interactive table to view, rank compare the set of all 100 districts.   Use the table to view how these districts are changing over time.  These data are based on enrollment reported by individual school districts and will update in spring 2014 with 2013-14 enrollment data.

In several states, school districts are coterminous with county boundaries.  As a result, Florida has 14 districts in the list of largest 100, followed by Maryland (6) and Virginia (6).   In most states, school district boundaries are not coterminous with city or county boundaries.   Many states have maintained a heritage of mostly small school districts.  Several states with districts in the largest 100 set do have some districts that are county equivalents (Philadelphia, PA and Cook County, IL).

In contrast, Texas, which has no larger districts that are coterminous with county boundaries, has 19 districts in the largest 100 set.  California, with very few districts coterminous with counties, has 12 districts among the top 100 set.

See additional tables and more information about school district demographic-economic characteristics described in the school district community information resources.  

10 Reasons to Avoid ZIP Code GeoDemographics

Possibly the most obvious reason to use ZIP codes for small area demographic and economic analysis is that the analyst has ZIP Code-based data. Typically those data are addresses or address-based data.  The analyst seeks to assign demographic and economic data to the ZIP code records/locations so that more can be known about the demographic-economic characteristics of individual addresses or address vicinity.

ZIP Codes are well known to all of us. They are used by the U.S. Postal Service as a means to more efficiently deliver mail.  Census tracts may be less familiar. Census tracts are defined by the Census Bureau and organized as sub-county building blocks.  More about census tracts.

This sample profile shows side-by-side comparison demographic-economic views of two census tracts and associated ZIP Code Tabulation Area in the Scottsdale, AZ area.  See related section about equivalencing census tract and ZIP Code area geography.

10 Reasons to use Census Tracts Versus ZIP Code Geography & Demographics

1. Census tracts are polygons and cover a well-defined geographic area.
ZIP codes are clusters of lines; the U.S. Postal Service does not define ZIP Code boundaries.  A very large number of 5-digit ZIP Codes are P.O. boxes or specific street addresses and thus represent points not even one line.
2. Census tracts provide more granularity (73,000 areas) than ZIP Codes (43,000).
3. Census tracts are, generally, non-changing static geography from decennial census to census.  ZIP codes may change at any time; new ZIP codes may be created or eliminated at any time.
4. Census tracts cover the U.S. wall to wall.  ZIP codes exist only where U.S. mail service is provided.
5. Census tracts align coterminously to county boundaries.  ZIP codes do not.
6. Census tracts have well known/exact boundaries.  ZIP codes are groups of lines whose exact structural definition is not officially established.
7.  Census tracts provide more statistical uniformity averaging 4,000+ population.  The population of a single ZIP code can exceed 100,000.
8.  Census tracts have a large and richer set of associated, more reliable demographic-economic data. True ZIP Code data are only delivery statistics developed by the U.S. Postal Service.
9.  The total land area and water area are known for each census tract, to the square meter.  The total area covered by a ZIP Code is not known, let alone water area.
10. A unique set of census blocks, and hence demographics, can be associated with each census tract.  There is no good way to associate census blocks with ZIP codes.
11.. Who’s counting? It is entirely feasible to develop and analyze time series data for census tracts.  Time series data by ZIP code is risky due to the inherent potential for changing geographic scope.

So why do we keep using estimated ZIP Code areas and demographics? In the main, ZIP codes provide an easier and more comfortable way to associate or characterize demographic-economic conditions.  We all know our own ZIP code and generally quite a few others.  Few among us know what our census tract code is, let alone for other locations.

Hispanic Population by Specific Origin by County

The Hispanic or Latino population group is comprised of many specific origin subgroups. The specific origin subgroups are often associated with different regions of the world. Many specific origin subgroups tend to cluster by location within the U.S. both as a result of the geography of emigration (e.g., Mexico to Texas) and association with where same subgroup emigrants have settled (e.g., Cuba to New York).  Census 2010 identifies approximately 70 Hispanic specific origin subgroups.

Use the interactive table at http://proximityone.com/hispanic_origin.htm  to gain insights into how the Hispanic specific origin subgroups are distributed across the U.S. by county. Tools are provided to analyze geographic and subgroup patterns of interest.

State Median Household Income Continues Decline

From 2000 to 2012, real U.S. median household income decreased 6.6 percent. The U.S. median household income decreased from $55,030 in 2000 to $51,371 in 2012. 35 states showed statistically significant decreases in real median household income from 2000 to 2012. These data are based on American Community Survey (ACS) estimates (more about the latest ACS 2012 data). Use the interactive table to examine the population components of change for the U.S. and by state.