 The island's mastic production is controlled by a co-operative of medieval villages.The local producers are united under the Chios Gum Mastic Growers Association.Founded in 1938, the Chios Gum Mastic Growers Association (), abbreviated "CGMGA", is a cooperative organisation and acts as the collective representative organ of twenty primary cooperatives totalling nearly 5000 members in the twenty-four villages of southern Chios.