 held by an individual supplier decreases. 1971. Licences were granted to specialised common carriers to Furthermore the new service providers may take business from an provide switched telecommunications services connected to established PTO, but they provide him with increased revenue by existing local networks. This was the specialised common using his network to carry these new services (Aamoth and Smith, carrier decision. In the same year the integrated office automat- 1991). The problem the regulator faces is to determine the rate at ion systems market was opened to competition (Computer which the market should be opened to competition. If, after a second Inquiry AT&T was allowed to supply these services through supplier has been introduced, a third supplier is granted a licence, independent subsidiaries only. he is more likely to take business from the new entrant than from 1976. The market for terminals was opened further by simplifying the established PTO. the certification procedures. This was referred to as the equip- The world population is about five billion, and it has a GDP of ment registration programme. approximately nineteen trillion dollars. The world communications 1980. Introduction of the concept of value added services, cover- market is about five hundred billion dollars. The North American, ing basic services and enhanced services. The terminals market European and Japanese markets account for about 15% of the world was deregulated and AT&T was allowed to enter this through population but they represent over 60% of its GDP and over 90% of independent subsidiaries, only. the telecommunications revenue. 1982. Ruling by the District Court for the District of Columbia that the regional Bell system had to be split off from AT&T. The 11.3.1 long distance services of the Bell system, as well of the Bell Laboratories and Western Electric were to be retained by AT&T. Competition was subsequently introduced in the long The USA telecommunications market is the most liberalised in the distance network