CityLab finally allowed for an official response defending historic districts, after their writer Kriston Capps threw them under the bus. Just to recap, this was an article charging that historic districts in Michigan and Wisconsin are the cause of the affordability crisis in San Francisco or Boston.
Stephanie Meeks of the National Trust for Historic Preservation wrote this excellent article that is now up on the CityLab site. Within the extent of her article, I think that this is the salient point:
Second, while we share the concern about the affordable housing crisis gripping the nation, getting rid of historic preservation districts is not the answer. Economists such as Edward Glaeser have argued that historic districts prevent affordability by limiting tall and dense new development that could fit everyone. But, as the urban planner Jeff Speck points out in Walkable City, “economists don’t seem to have fully processed one thing the designers know, which is how tremendously dense a city can become at moderate heights. Boston’s North End, in Jane Jacobs’ day, achieved 275 dwelling units per acre with hardly an elevator in sight.”