Walkable communities show higher property values in Vermont and Puget Sound?

Below is an excerpt from an interesting  article, http://www.peoplepoweredmovement.org/site/index.php/site/blog/3953/:

“RSG also cross-referenced the closing prices on real estate with the Walk Score of those locations. On average, the property values of homes in walkable neighborhoods were $6,500 higher than those in car-dependent areas. Add all those homes together and walkability added more than $350 million to the local economy”.

I would be curious as to the the home valuation differences between auto and non-auto dependent Seattle area neighborhoods. I believe that the “walkability” factor contributes to differences in median prices, but let’s *compare two similar (similar age range of homes, Mill Creek contains a few larger lots) north end communities to see:

(19) Mill Creek: Has a walkscore of 34 (out of 100), so is “car dependent”.  In 2011 – 19 homes sold with a $279,950 median sold price and 112 median  days on market. The median square footage was 2042sf. The result is $137.09 per square foot.

(15)  Edmonds Bowl/Downtown Edmonds: Has a walkscore of 50 (out of 100), so is “somewhat walkable”.  In 2011 – 68 homes sold with a $452,000 median sold price and  82 median days on market. The median square footage was 2617sf. That comes out to $172.71 per square foot.

* Calculations above were based on numbers derived from the Northwest Multiple Listing Services. They are deemed reliable, but not guaranteed.