Definition
Main economic activity refers to the activity that contributes the biggest or major portion of the gross income or revenues of the establishment.
Establishment - an economic unit engaged in one or predominantly one kind of economic activity under a single ownership or control at a more or less fixed location, e.g. farm, mine, factory, store, bank, restaurant. For multi-unit enterprises with different outlets and subsidiaries or whose activities are located at different locations, each branch, outlet or subsidiary is considered an establishment. For firms engaged in activities which may be physically dispersed such as mining, construction, real estate development, transportation, communication, insurance, etc. the establishment is the base from which the personnel operate to carry out their activities or from which they are paid.