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Telephone directories and the productive benefits of mobile phones

Mobile phones have radically changed lives in sub-Saharan Africa. However, in rural communities, the lack of telephone directories listing phone numbers for services and businesses can reduce the productive benefits of mobile phones. Brian Dillon, Assistant Professor of Development Economics and Applied Econometrics at Cornell University, discusses a DEEP research project that is assessing the impact of providing rural farming households with access to a telephone directory service.

When mobile phones swept through the developing world in the late 2000s, they opened up new possibilities. Every new mobile tower brought the prospect of low-cost connections between rural populations and the broader world through personalised, two-way communication. Hundreds of mobile-based programmes have been launched since then, providing health advice, weather forecasts, crop prices, and a wide range of other services. Smartphone apps have been developed to help firms manage costs, help farmers identify pests, and help healthcare workers track vaccines.

Despite some initially exciting findings – for example, early studies in economics (such as Jensen 2007 and Aker 2010) demonstrated the power of mobile phones for improving the efficiency of markets – it has proved difficult to find positive impacts from the many phone-based services that have materialised across sub-Saharan Africa over the last 15 years. Most programmes have not been formally evaluated, and among those that have, the results are mixed, at best. Assessing how mobile phones can best be utilised to improve livelihoods remains a challenge.

When we interviewed rural Tanzanians during the early years of the mobile phone revolution, we found that most called only a handful of other people, and those tended to be people that they already knew. Phones were not widely used for productive purposes. According to those early interviews, respondents could not call unknown businesses or people because they did not have anyone’s phone number, and had no easy way to get new phone numbers.

The problem facing our early interviewees is widespread. Mobile phones have rolled out across sub-Saharan Africa without a complementary information service (for example the Yellow Pages) to help phone users find new contacts. Printed telephone directories are sometimes available for landline phones in major cities, but those include only a small fraction of businesses, and the directories are not widely distributed. The Internet is of limited use to date, as most of the businesses that are relevant for the day-to-day lives of poor households have no web presence. Smartphones are popular among middle- and upper-class urban residents, but the overwhelming majority of rural residents still do not have a smartphone (in a 2022 survey we conducted with over 3,300 rural Tanzanians, only 6% had and used a smartphone). With no service to gather and curate contact information, most mobile users either save useful numbers that they see when travelling (for example, on signs or in shops), or ask members of their face-to-face networks to share contact information.

This stands in stark contrast to the way that landline telephones spread through currently wealthy countries over a century ago. Landlines were always accompanied by another service – a local directory booklet, an operator, a large Yellow Pages or a web directory – to help phone users search for new contacts. Without such services, we became concerned that the benefits of mobile phones may accrue disproportionately to the wealthy and well-connected. And at a broad level, it seems inefficient to build an entire system of global communication without providing a basic (and relatively cheap) information product that helps people use it effectively.

Through a series of randomised experiments in Tanzania, our team has sought to measure the importance of telephone directories. Our focus is on Yellow Pages-style directories that contain information about businesses. We are interested in measuring the impacts of directories on both the firms listed in them, and the households that receive a copy.

We began our first experiment in 2014, in parts of the Dodoma and Manyara regions. We conducted a census of enterprises in eight sectors relevant to farming households (we had to conduct our own census because there are no comprehensive databases of small businesses in Tanzania) and used the information to print a Yellow Pages directory called Kichabi (from the Swahili kitabu cha biashara: ‘business book’).

We found that the directory listings were highly impactful. The listed firms received more calls, made more sales, and made greater use of mobile money than unlisted firms. These impacts did not come at the expense of the unlisted; our evidence indicates that the widespread reduction in search costs generated additional economic activity, without taking business from unlisted firms in the short run. Directory users benefited too. They searched more widely for buyers of their crops, ordered more goods for delivery to the village, and invested more in their farms. And they used the directory to find better trading partners.

In a series of follow-up studies, we have demonstrated the feasibility of a digital directory that can be accessed on any mobile phone, examined how firms that receive access to the directory change their business practices, and measured firm willingness-to-pay to be listed in the directory. At present, we are running a multi-year study in the Kagera region to better understand what types of households benefit most from receiving a directory. The results of that study are expected in 2025.

A telephone directory strengthens local networks, allowing residents to find and communicate with each other. In this sense, directories are an essential part of information and communications technology infrastructure. Until they are widely available, we should not expect mobile phone networks to achieve their full potential for transforming lives and unleashing economic development.

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