I have read the research associated with this article. It attacks Green zones as a problem. Well folks, Green zones are not the problem; the single family dwelling is the problem. The single family dwelling is the economic, social and environmental scourge of urban areas and suburbia. Especially over the last 25 years, 905 municipalities and the OMB have allowed developers to squander green space by developing massive subdivisions of single family dwellings. Such developments should have been banned long ago. The lowest allowable density should be a row house. The most common unit,  the low rise condo. Nothing short of taxing single family dwellings out of existence, and banning their construction will alleviate the housing shortage.