Oregon Census Tract Map: The Rate of 2008 HUD Housing Vouchers Per 100 Occupied Rental Housing Units in 2000.

I have created a new map (Google Fusion table link is HERE ; map legend and embedded map are below) that shows the rate of HUD housing vouchers in 2008 per 100 occupied rental units in 2000 for all Oregon Census Tracts.  

I believe this is the first time any web map/table with HUD voucher data for all of Oregon census tracts has ever been publicly posted. As with many other projects posted on the blog this map is intended to demonstrate what is possible --I encourage others to build on what I have posted.

Notes: 

1. Statewide in 2008 there were 6.5 HUD housing vouchers for every 100 rental housing units that were occupied in 2000. (31,215 vouchers/476,772 occupied rental housing units).
2. The census tract with the highest concentration of vouchers is 41051008901 in SE Portland. It had 113 vouchers in 2008 and as of 2000 there were 349 occupied rental housing units; using this data the rate of vouchers per 100 renter occupied housing units was 32.4. (See Important Caveats section below).
3. At the bottom of this post I explain the methodology used to create the map. 
4. A Google account is likely required to view/work with the Google Fusion files. 
5. When in the map if you click a census tract you will see the CT name and city, if any, and the 2008 count of vouchers; the 2000 Census count of rental occupied and home owner occupied units; and the rate of housing vouchers per 100 occupied rental units.

IMPORTANT CAVEATS:  

1. Voucher data is as of 2008, while counts of rental units are from 2000 Census. As the number of occupied rental units in Oregon increased by 20.5% (97,685 units) from the 2000 to 2010 Census, the rate of voucher units per 100 occupied rental units in 2008 is overstated statewide and in a variable way at the census tract level. Using the Census 2010 count of 574,453 occupied rental units the statewide rate of 2008 vouchers per 100 occupied rental units would fall from 6.5 to 5.4 per 100 occupied rental units. 
2. Because the addition of just one rental housing project between 2000 and 2010 could significantly change the voucher rate per 100 occupied rental housing units at the census tract level, extreme caution should be used in drawing final conclusions about the rate of voucher use at the census tract level. For census tracts with apparent high rates of voucher usage I would check other resources like ACS to see if the count of occupied rental housing units has changed significantly from 2000. (For example, for the CT with the highest apparent rate of usage [41051008901] ACS 2005-2009 data HERE shows an estimate of 708 occupied rental housing units; this is 74% more occupied rental units than the 349 counted in the 2000 Census. This higher count of occupied rental housing units would DECREASE the rate of vouchers per 100 renter occupied units from 32.4 to 18.6).
3. In a subsequent post I will include a link to a table showing what the voucher rate per 100 rental units was by county using actual occupied rental housing counts from the 2010 Census.
4. My hope is that the next set of HUD Picture of Subsidized Housing data will count voucher units using 2010 census tract boundaries so that the higher count of Census 2010 occupied rental housing units in each census tract can be used in a revised set of CT level maps.
5. The map and table do NOT include project based HUD rental units. Voucher counts only include counts where census tracts are identified; it is possible that other HUD databases may include counts of voucher units without identified census tracts.

Methodology

I recently downloaded a national HUD file HERE with 2008 housing voucher counts and related data down to the census tract level. Using that data and others I then created and uploaded a CSV file to Google Fusion that included

1. Census 2000 counts of occupied housing units by tenure.
2. The count of HUD vouchers in each census tract as of 2008.
3. A calculated ratio of HUD housing vouchers per 100 occupied rental housing units. 

Using free Shpescape.com and Google Fusion "cloud" software tools I then uploaded a SHAPEFILE of 2000 Oregon census tracts boundaries and merged that data with the housing voucher/housing unit count file that I had previously uploaded. From the merged table I then used the visualize tools in Google Fusion to create the map embedded in this post.

Originally created and posted on the Oregon Housing Blog.