OISL's Interactive-Voice-Response Campaign — A Randomized Trial That Nearly Doubled Mobile-Banking Use Among Low-Literacy Ghanaian Borrowers

OISL, a rural lender licensed by the Bank of Ghana in 2004 and serving low-income, often low-literacy clients across most of Ghana's regions, partnered with researchers from Innovations for Poverty Action and J-PAL to test whether phone-based information alone could raise use of a mobile-banking channel that avoids branch visits, paperwork and reading requirements.

15,000 clients were randomly assigned in August–November 2020 to three groups: 5,000 received ten weekly interactive-voice-response (IVR) calls, in local language, explaining mobile-banking benefits and how to use the service; 5,000 received IVR calls with general savings advice as an active control; 5,000 received no calls. Outcomes were measured through April 2021.

Clients who got the mobile-banking calls were 6.3 percentage points more likely to transact that month, versus 2.4 points in the comparison group; average monthly transactions roughly doubled (0.075 to 0.15) and average transaction value roughly tripled ($1.76 to $6.40). Late loan repayment fell 2.4 percentage points, an 8% relative drop from a baseline near 30%, improving clients' access to follow-on loans. The intervention cost roughly $0.28 per customer per month. The savings-advice-only calls produced no measurable behaviour change, and neither treatment arm increased savings balances — a limitation the researchers report without softening it.

The trial was pre-registered with the AEA Social Science Registry, and the results were published in the peer-reviewed journal Economic Development and Cultural Change (Riley & Shonchoy, 2025); the paper reports the mobile-banking effect persisted at 9-month follow-up, with treated clients 2 percentage points (11% relative) more likely to still hold a bank loan.

Read the full analysis: https://ideas.repec.org/a/ucp/ecdecc/doi10.1086-732597.html