Navigating borders/navigating networks: migration, technology and social capital

Telecommunication operators have a unique perspective on human mobility; they know the locations of their customers, for most of the time. In recent years, a number of initiatives were organized by telecommunication operators in which mobile call data records (CDR) were carefully anonymised, aggregated, and opened to researchers in form of a challenge for providing new insights into people's movements and displacement patterns. An example is the Data for Refugees Challenge, organized with the expressed aim "to improve the living conditions of over 3.5 million Syrian refugees in Turkey". Typically, the mobile phone datasets collected by a telecommunication operator only include movement patterns observed within a single country, but with additional assumptions, it is also possible to gain insights into movements across borders. This chapter provides an historical overview of research on mobility analysis through mobile CDR, highlights practical issues such as data gaps and biases, discusses ethics and privacy principles that must be taken into consideration when working with such sensitive data, and argues that migration studies and humanitarian response projects may benefit greatly from the use of real-time or historical mobile CDR data.