Nobody wants to work outside at wages so low.

A co-worker years ago was the son of a construction worker. One winter his father was on a job site in New York, within easy view of an office building. Some of the clerical staff in an office put up a sign in the window: "It's 70 Degrees In Here". The construction workers put up their own sign: "It's $X/hour Out Here", $X being considerably higher than the going wage for clerical workers.