Relaxing allowed uses might help in a few places, but probably not. The reason obsolescent retail sites sit abandoned is mostly that they are obsolescent retail sites, not restrictive regulations.<p>The market incentives of real-estate are to develop parcels to their highest and best use. Retail is one of the highest and best uses. The economics mean that a 20% chance of putting a thriving retail use on a retail site in the next 15 years has a better upside than a 60% chance of putting housing on the site in the next eight years. And eight years is relatively quick from the back of napkin to money in the bank for a substantial real-estate development and twenty years is not atypical.<p>Land development regulations are a hurdle in real-estate development but not usually the determining factor. The cash to purchase a suitable site, build it out, and market it is more significant. Avoiding the down-trough of real-estate cycles and the peaks of construction demand and bubbles in the market sector are probably the most important thing...bad luck is ordinary not a black swan.<p>I'd put it another way, if regulation was the barrier to repurposing obsolescent retail, the real-estate professionals would head down to their local planning department with pitches for beneficial new uses and local cable broadcasts of planning commission and city council meetings would be filled with contention over obstructionist regulations preventing down zonings.