Dr Madsen Pirie's comments on the greenbelt feature in the International Business Times UK:
"The first step in re-evaluation might be to classify greenbelt land into the different types that comprise it," wrote Dr Madsen Pirie of the Adam Smith Institute think tank back in March.
"There is genuinely green land, the fields and woods that everyone likes. There is damaged or brownfield land, partly made up of abandoned buildings, gravel pits and the like. And there is farmland, much of which is not environmentally friendly."
An earlier report by the Adam Smith Institute said that one million homes could be built within walking distance from a station on just 3.7% of the green belt land surrounding the city.