average income and rent by seattle light rail station

Light Rail Income Inequality

The New Yorker has a visualization that map incomes by subway lines while the BBC posted a graph that shows median monthly rent by subway stop.

How would one go about creating a similar visualization for Seattle with its new and expanding light rail system? Where would you get the necessary data to create such a visualization? What would be the most effective way of representing the impact of light rail on income and housing cost?

To sketch the concept, I created these graphs below that chart household income within a half mile of light rail stations and a second graph that displays average rents. There is a lot of problems with the data used to create these graphs. I hope anyone with interest in this project would be willing to contact me to consider other approaches.

Median Household Income Within 1/2 Mile
2010 Median Household Income Within 1/2 Mile of Light Rail Station
I used a tool called FreeDemographics.com to lookup household income by radius. The tool purports to use 2010 Census data, but I’m making assumptions about how they’re generating data for such a low level of granularity. What would be a more accurate, verifiable, and repeatable way to generate data about household income within a radius of light rail station? Does a half mile radius even make sense in a city that is so hilly? How about generating demographic data from within a 15 minute walk from the light rail station?

Median Rent Price of Listings Nearest Light Rail Station
Median Rent Price of 20 Listings Nearest Light Rail Station
I have no idea if this data is reliable at all. Ideally I want a tool that allows me to look-up average rent over the past 12 months within 1/2 mile or 15 minutes walking distance from the light rail station, but all I could find is the Rentometer. The tool lets you get 20 results nearest an address. The sample size is too small for a reliable picture of median rent and besides it would be more helpful to compare the same size units (1 or 2 bedrooms) across stations.

Observations based on the graphs above
It surprised me to see Tukwila International Blvd Station boast the highest household income and the lowest median rent. While this suggests cost of living is lower outside the city of Seattle, the high rent and low income by University Street Station speaks of income inequality to me. This probably reveals my biases in interpreting this visualization, but it would be interesting to investigate further.

Next Steps
In addition to improving the method of acquiring and transforming this data, I’d like to start collecting average housing cost and income for future light rail stations. It would be very interesting to be able to map the fluctuations in housing costs and household income over time with a view to the impact of Link Light Rail on income inequality and affordable housing. If you’re interested in working on this with me, please let me know!