Recently, there was an interesting story on Chron.com analyzing the retail growth currently being experienced by Houston suburbs. On the surface, this is a fairly easy conclusion: retail is booming in the suburbs because that's where the people live and people want to shop near to their residences. Unfortunately this isn't a theme that jives with the mantra of New Urbanism so the chron.comments area river of fire.
I've linked before to this Keep Houston Houston post about ethnic diversity in Hosuton's Suburbs vs. it's inner, urban core and I believe it's pertinent to the results found here. Big box retailers love diversity, it provides a fruitful market for a variety of goods and services which allows them to keep shelves well-stocked. For the most part, niche, small stores tend to serve a much narrower demographic, so they tend to locate near where that target demographic resides. Pedestrian Pete may have a desire to walk into a gourmet, fake-French Bistro in Houston's museum district for an espresso and croissant but the average Houston-area resident is just fine driving through some chain to pick up a coffee and breakfast sandwich. Of course, Pedestrian Pete doesn't work any longer, is very wealthy, and spends considerable time in the South of France luxuries not enjoyed by a vast majority of the citizenry.
For the average Houston-area work-a-day citizen that breakfast trip is just a precursor to trying to get everything done on Saturday. While the fedora wearing Pete is sitting idly and watching the world go by Johnny suburb is running to Home Depot to grab a part to fix a toilet, heading to the store to pick up a last minute item for lunch, taking the kids to the mall to buy new shoes because the ones they have are wearing out and trying to decide what his family is going to eat for lunch today because there probably won't be time to cook for them given their busy schedule.
Based on that schedule, they're more likely to head to a big-box department store for their purchases than they are to hop-scotch their way through several boutique stores all while trying to find a good parking spot that won't result in the City of Houston issuing them a violation.
When you take those items into consideration it's no wonder the outlying cities are out-pacing Houston in terms of retail growth. They're meeting the needs of the market, which is nothing more than economics 101.