There are strong connections between walkable environments and economic viability.
"Real estate values over the next 25 years will rise fastest in "smart communities" that incorporate traditional chareacteristics of successful cities including a mix of residential and commercial districta and a "pedestrian-friendly configuration." - Walkable Communities, Inc.
Two studies shed light on the issues of Walkability and can be downloaded from the sites below:
From the Local Government Commission, The Economic Benefits of Walkable Communities.
From Smart Growth America, Foot Traffic Ahead.
Walkable communities are not just wealthier, but healthier. More here and here.