Retail space in Arizona must be savagely vacant. So many vacant buildings! So many marginal businesses! (Pawn shops, thrift shops, etc). Assume vacancy varies with age of structure, so that the older buildings are the more vacant. But still! It makes so many marginal businesses possible.
Development is the competition between parcels (via their owners) for value adding development?
Sometimes the disamenity of proximity is sufficient to prevent adjacent land from developing. Where the land is cheap...