One convenient measure of the interconnectedness of the world is the number of telephone lines per person. Telephone mainlines are telephone lines connecting a customer's equipment to the public switched telephone network.

Maps on this page show how this measure has changed over the decades from 1960. The data show a steady increase in connectedness. Numbers of telephone lines appear to be rising in every country. The rising availability of cell phone service, even in poor countries, may mean that numbers of mainlines is an underestimate of the increasing access to telephones. In Bangladesh, for example, the Grameen (village) Bank is renting cell phones to villagers who then carry the phones around to those who wish to make a call.

We have mapped these data using the following intervals:

In 1960, much of the industrialized world had 150-300 mainlines per 1000 people while most of the rest of the world had less than 50 connections per 1000 people. In 1998, eastern Europe and South America had achieved levels similar to that of the industrialized world in 1960. The industrialized group of countries was by 1998 reaching levels approaching 1 line per person or 1 line per two people. South Asia and Africa have far fewer lines per person.