Migrant by Proxy: How Big Data Defines and Redefines Human Mobility

In big data systems, migrants rarely appear as self-identified social actors. Instead, they are rendered through proxies such as social media traces, mobile phone records, or online behavioural signals. We introduce the concept of the migrant by proxy to examine how such indicators do more than approximate migration: they shape what migration becomes measurable, visible, and governable. Across discursive, behavioural, infrastructural, and demographic perspectives, we argue that proxies function as technical indicators, epistemic operators, and governance devices. While analytically valuable, they structurally exclude key populations and cannot capture migration as lived experience, requiring stronger standards for validation, triangulation, and accountability.