Mobile phone use in Africa is growing faster than anywhere else in the world, according to a report.
Many businesses in Africa rely on mobile phones, the report says
The study, backed by the UK mobile phone giant Vodafone, said African countries with greater mobile use had seen a higher rate of economic growth.
The report, supported by the Centre for Economic Policy Research, studied the social and economic impact of mobiles.
Small businesses in South Africa rely on mobiles, the report said, while Nigeria's market is doubling annually.
The report's positive findings come despite separate figures which show the proportion of people using mobile phones in much of Africa remains low in international terms, averaging about 6% in 2004.
Mobile and land line networks - in addition to the openness of an economy, GDP growth and infrastructure - are positively linked with foreign inward investment, according to the report.
The report also said:
- More than 85% of small businesses run by black people, surveyed in South Africa, rely solely on mobile phones for telecommunications.
- 62% of businesses in South Africa, and 59% in Egypt, said mobile use was linked to an increase in profits - despite higher call costs.
- 97% of people surveyed in Tanzania said they could access a mobile phone, while just 28% could access a land line phone.
- A developing country which has an average of 10 more mobile phones per 100 population between 1996 and 2003 had 0.59% higher GDP growth than an otherwise identical country.
Income, gender, age, education - and even the absence of regular electricity supplies - do not create barriers to mobile access in rural areas, the report said. Handsets are often shared by smaller communities.
Stephen Yeo, chief executive of the Centre for Economic Policy Research, which hosted the launch of the report on Wednesday, said mobile phones had enabled developing countries to "leapfrog" old technologies.
Kiosks selling pre-pay vouchers for mobile phones are common
"The result is explosive growth - 5,000% in Africa between 1998 and 2003," he said.
"This research... provides the first empirical evidence of a link between social and economic development and the establishment of mobile phone networks."
Diane Coyle, of consultancy Enlightenment Economics, and author of the report's overview, said many people were finding ways to overcome the cost of making mobile calls.
"Even in very poor communities, a lot of people share mobile phones," she told the BBC's World Business Report. "In Tanzania, for example, there were as many people using somebody else's mobile phone as actually owned one."
Currently, there are more than 82 million mobile phone users in Africa.