Programming and Input-Output Models
Output normally refers to total production of a country. The total production is composed of production in three major sectors:
(a) Primary sector including agriculture, irrigation, animal husbandry, forestry, fisheries, and mining/quarrying;
(b) The secondary sector referring to industry including processing and manufacturing, generation of electricity, gas, water, etc. and also ‘construction’;
(c) The services sector comprising transport, communications, trade, commerce, finance, law & order/legal, etc.
The primary sector thus refers to activities in which products derived from natural resources like land, water and animals are included. The secondary sector refers to products derived by a process or an operation (like processing or manufacturing) on the products extracted from the primary sector. The services sector includes activities in which the products derived from the primary and secondary sectors are distributed to various intermediate and final points of consumption besides providing various other services to producers and consumers.