Networks of monetary flow at native resolution

TL;DR

This paper analyzes mobile money transaction data to reveal large-scale monetary flow patterns, network structures, and temporal heterogeneity, providing insights into economic activity and potential gaming behaviors.

Contribution

It introduces a method to trace and analyze transaction sequences in mobile money systems, uncovering distinct network motifs and behavioral patterns.

Findings

Different mobile money activities create unique network structures.

E-money passes through the system in times ranging from minutes to months.

Detected coordinated gaming of the provider’s commission schedule.

Abstract

People and companies move money with every financial transaction they make. We aim to understand how such activity gives rise to large-scale patterns of monetary flow. In this work, we trace the movement of e-money through the accounts of a mobile money system using the provider's own transaction records. The resulting transaction sequences---balance-respecting trajectories---are data objects that represent observed monetary flows. Common sequential motifs correspond to known use-cases of mobile money: digital payments, digital transfers, and money storage. We find that each activity creates a distinct network structure within the system, and we uncover coordinated gaming of the mobile money provider's commission schedule. Moreover, we find that e-money passes through the system in anywhere from minutes to months. This pronounced heterogeneity, even within the same use-case, can inform the modeling of turnover in money supply. Our methodology relates economic activity at the transaction level to large-scale patterns of monetary flow, broadening the scope of empirical study about the network and temporal structure of the economy.