Using election registration data to measure migration trends in South Africa

Abstract

Migration is an issue that remains critical for policy agendas and government planning. Over time migration, in addition to population growth or decline, changes the demographic composition of towns, cities and regions which in turn requires adjustments to service and infrastructure provision. In order to be forward-looking and to develop suitable policy responses, reliable comparable and timely information is required. The most obvious sources of migration data used to be the national census (held every 10 years or so), as well as household and labour surveys (other surveys mostly extend to particular parts of South Africa). Although socio-economic data has increased, it has not dealt well with migration. A recent research project conducted at the CSIR entitled the Spatial and Temporal Evidence for Planning in South Africa (StepSA) project explored the use of voter registration information as an alternative source for migration data. Anonomised voter registration data was provided by the Independent Electoral Commission of South Africa for several consecutive elections covering an 11-year period. The data, once spatialised (and related to a single set of voting districts), could then be processed to extract movement trends between different election periods. This article outlines the process applied and describes the initial analyses conducted.