This facility near Bluff, Southland, is one of the largest aluminium smelters in the world and employs nearly 1,000 people. In 2009 it was owned by Rio Tinto Aluminium, based in Brisbane, Australia, and Sumitomo Chemical Company of Japan. Gross domestic product (GDP) measures all the income and profits earned by the smelter’s production. To understand the impact of such ventures on New Zealand residents, the profits sent overseas to the foreign owners must be excluded. Unlike GDP, gross national income (GNI) excludes the earnings of foreign residents.