It should, however, be noted that there is more to the reasons why the headquarters functions of industry and business are concentrated in the capital, especially in such areas as Marunouchi and Otemahci, than just easy access to governmental power. As decision-making points and command posts, headquarters functions come to congregate in certain locations so as to establish the best access to business information, both domestic and international. In the age of telecommunications and computerization, nothing is more precious than business lead-time. Financing its business is, perhaps, by far the most important function of all business administration. Tokyo has been the largest financial centre of the nation for a long time, but since the 1980s Tokyo has become one of the key international financial centres and the Tokyo Stock Exchange exceeds the New York Stock Exchange with respect to stock volumes and stock values.
Financial business is also the forerunner to implementing information technology.
In the age of international business and telecommunications, these investments are unavoidable. Thus they create more demand for IT-based producer service industries in the area. Third, banking and insurance are not the only businesses to have been highly computerized. The distribution system in Japan used to be one of the most complex systems. Each industry and its subgroup had its own distributional network, and these differed by region.