(C ) Improvements in worker health from better nutrition
Robert Fogel, an economic historian, and Noble prize winner for Economics, is best known for suggesting that a significant factor in long-run economic growth is improvements in worker's health from better nutrition, he was of the opinion that malnourished workers cannot perform manual labor, because they don't have the strength and stamina, and this will affect productivity. He believed that as nutrition improve, so will worker's productivity.