Legal Sanction: A monopoly as stated above may be the result of a government sanction. The government of a country may legally permit a private monopoly or monopoly in the public sector for myriad reasons. National security (e.g. manufacture of defense equipments), social equity (post office, water supply, electricity supply, telephones) or economic considerations (public utility services or essential goods to be produced on a large scale by a single firm for reducing the cost and price e.g. monopoly of transportservices) are paradigms of such monopolies. Monopolies may be created to avoid wastes due to duplication of services e.g. public utilities.