A Los Angeles Times editorial calling on city leaders to make it easier to legalize backyard homes cited research by urban planning professor Vinit Mukhija, an authority on the informal economy of un-permitted housing units. Accessory dwelling units, or ADUs, are a relatively easy way for Los Angeles to add more housing at a lower cost. L.A. had at least 50,000 un-permitted secondary units on single-family lots in 2014, according to research by Mukhija, author of “Remaking the American Dream,” a new book on the transformation of an urban landscape once dominated by single-family homes. While recent state laws have eased the process of legalizing ADUs that were built without a permit, regulations in the city of Los Angeles continue to be complicated, time-consuming and expensive, the editorial maintained. It urged city leaders to do everything in their power to help property owners bring their un-permitted units and tenants out of the shadows.