“What becomes of the ground-floor city when retail mutates into new forms? Some luxury brands might keep their boutiques as indulgences and loss leaders. But as national chains’ contracts give up on physical locations, commercial rents could fall, clearing the way for a resurgence of small stores: designer cookies and pet spas, but also used-book stores and shoe-repair shops. Or maybe only bars and restaurants will survive, and we will repurpose vacant storefronts into living spaces for a housing-strapped city.”