Long and detailed (of course) story from The New Yorker about malls, by Malcom Gladwell.
Then he looked up and pointed to the second floor of the mall. The handrails were transparent. “We don’t want anything to disrupt the view,” Taubman said. If you’re walking on the first level, he explained, you have to be able, at all times, to have an unimpeded line of sight not just to the stores in front of you but also to the stores on the second level. The idea is to overcome what Taubman likes to call “threshold resistance,” which is the physical and psychological barrier that stands between a shopper and the inside of a store. “You buy something because it is available and attractive,” Taubman said. “You can’t have any obstacles.”