Using mobile money data and call detail records to explore the risks of urban migration in Tanzania Rosa Lavelle-Hill, John Harvey, Gavin Smith, Anjali Mazumder, Madeleine Ellis, Kelefa Mwantimwa and James Goulding EPJ Data Sci., 11 1 (2022) 28 Published online: 08 May 2022 DOI: 10.1140/epjds/s13688-022-00340-y