The evolution of migration trajectories of sub-Saharan African migrants in Turkey and Greece: The role of changing social networks and critical events.

• Migration trajectories of irregular migrants evolve non-linearly. • Social network dynamics and critical events explain how migrant trajectories evolve. • A typology is proposed to understand the varying role of networks for migration. • Networks mediate how migrants deal with critical events. While social networks have been widely argued to shape migrants' trajectories, their presence and their roles are not self-evident, nor constant. Common conceptualisations of migrants' social networks refer to the linkages between people in origin and destination countries. This underlies a rather linear notion of migration trajectories as a straightforward move from one country to another, and does not pay attention to the networks migrants have elsewhere in the world and those formed en route. This paper investigates how various network members and changes in migrants' social networks are associated with the evolution of their migration trajectories. It is based on ethnographic fieldwork and longitudinal social network analysis among 40 sub-Saharan migrants, part of whose trajectories in Turkey and Greece were followed over time. The migration policy environment in both countries is rather volatile, which is manifested in migrants' daily lives through the experience of critical events. Findings show that social network dynamics explain how migrants act upon these events and shape their migration trajectory accordingly. The findings question common representations of non-linear migration trajectories as the mere consequence of onward moves interrupted by policy constraints. By demonstrating the importance of changes that take place in networks and the timing thereof, it ultimately contributes to a better understanding of how non-linear migration trajectories evolve over time. [ABSTRACT FROM AUTHOR]