Guest post by Linnet Taylor, a Marie Curie postdoctoral fellow at the University of Amsterdam in Governance and Inclusive Development. Linnet's research focuses on the use of big data in the field of international development, and emergence of ethical frameworks to govern it. You can read more on her research blog.

Mobile phones have been hailed as an important shift in the way migration and related issues can be researched. However, the extent of the digital traces emitted by even the simplest phones mean that this trend is potentially transformative not just for for migration research but also for migration control. These traces therefore have huge implications for research ethics in the academic mobility studies community and beyond, amongst other interested organisations such as the UN (you can see a draft version of a paper on this issue here).

African migrants in Tel Aviv, Israel (Source:
Today, when migrants move, they are increasingly likely to bring a mobile phone with them; this includes undocumented movement. Consequently, mobile phone traces emerge as a powerful source of information not only for researching mobility, but also for tracking and controlling it. All phones connected to a network are constantly checking in with the nearest antenna, even if the owner is not making calls. Smartphones, which are more likely to identify their users through apps and more frequent contact with the network, are becoming more accessible. For example, the share of sub-Saharan Africans with smartphones is the world’s lowest at 10.9%, but has risen six-fold since figures became available in 2010.

This trend towards the use of phones is combining with an increase in the ‘datafication’ of surveillance and legibility, even in lower-income countries where much undocumented migration originates. Today, for instance, 48 out of 55 countries in the Sub-Saharan Africa region have SIM card registration, meaning that (despite an inevitable error rate) in theory every mobile phone signal emitted by someone from one of these countries, wherever they are located, is trackable to a particular identity.

For a researcher trying to determining a subject’s location using mobile data, two levels of specificity are possible depending on the type of data available. First, calling records show which network’s antenna is being used, and thus the user’s movement from the vicinity of one antenna to another. Second, more specific location data can be gathered as a phone’s SIM card automatically checks in with its nearest antenna. These data are particularly detailed in the case of smartphones, which auto-report their presence ten times per second.

These real-time data have, until recently, been accessible only to mobile providers themselves, governments and law enforcement, and (in the case of Apple devices) advertisers, but not to researchers or humanitarian organisations. Access to such data has started to change, however, since the 2010 Haiti earthquake demonstrated a strong case for the use of this type of continuous location data for humanitarian purposes, namely providing epidemiological data on the cholera outbreak that followed the earthquake. Next, mobile provider Orange released call data records from Côte d’Ivoire to researchers in its 2013 ‘Data for Development’ challenge, where of the 74 papers presented at the resulting conference, two thirds dealt with tracking mobility. Finally, researchers are using agent-based modelling to predict people’s mobility in cases of environmental stress or economic shocks. These three uses of data add up to what is potentially a perfect storm for migrants who wish to remain untrackable.

Mobile data tend to be controlled and distributed by corporations, who set the rules governing researchers’ access and restrictions on data use and sharing. However, governments have also had access to mobile phone geolocation data for some time. Free access was extended first to emergency response authorities during the 1990s, but later to law enforcement in general. It's potentially a short step to make it available to border control authorities in order to track migrants who are travelling irregularly.

These factors feed into several trends which are likely to affect undocumented migration in particular, and consequently, the research community focused on mobility. First, mobile phones are now the new passports. They identify, allow for real-time tracking and geolocation, and are unlikely to be discarded by undocumented migrants in the interests of anonymity. For an authority with access to mobile traces, every phone-carrying migrant is effectively carrying identity papers and using them to transmit his or her whereabouts up to ten times per second. Yet identifying migrants individually isn't even the most important feature of the new mobile identity paper; instead, this real-time geospatial tracking potential makes it possible to identify groups on the move, their speed and trajectories, and (through their service providers) their places of origin.

Second, in the much-quoted phrasing of surveillance scholar David Lyon, the ‘continuum between care and control’ which has always characterised surveillance is becoming increasingly blurred with regard to migration data. Research is increasingly focusing on mobile traces as a way to track movement, and new models make it possible to predict with some accuracy what will drive migration flows and where those flows are likely to be directed. These analyses are being done within academia, under the rubric of either development or public health research―fields which are conceptualised as highly ethical and responsible, yet whose research products may facilitate surveillance in profound and irreversible ways.

Third, the popularity and ubiquity of mobile phones may increasingly constrain corporations to align with state interests in terms of making data available to track and identify migrants. Mobile service providers are predominantly international companies, often with substantial interests or legal bases in high-income countries which have an interest in controlling migration flows out of lower-income regions. These mobile service providers have already been required to provide customers’ data to emergency response and law enforcement authorities, and if the inexorable logic of function creep applies here as elsewhere, the border authorities of individual countries, or combined efforts such as Frontex, will also eventually gain access to the real-time feed of migrants’ whereabouts.

The lesson for researchers is clear. If mobile data are released for research purposes under corporate auspices, there is the potential for those who analyse these data to be coopted into corporate and governmental goals with an unprecedented degree of efficiency. The label of ‘big data’ is currently a powerful one: research funding and high-profile publications reward those who come up with new ways to trace human movement and activities. Yet those who are able to do this ‘big data’ research are also often from academic disciplines without strong research ethics frameworks or enforcement mechanisms. For instance, computer scientists and mathematicians aren't subject to the same types of institutional review as social scientists, and those social scientists who collaborate on data science projects may also escape institutional review by crossing disciplinary divides.

It's therefore up to the mobility research community to track the development of this ‘big data’ research, to engage with it where potentially unethical directions are being taken, and above all, to critically analyse the ways in which state surveillance apparatuses are intersecting with corporate and academic interests. States have the will to control migration; corporations have the data. But the researchers who develop models and new analytical approaches are the essential third actor in these surveillant assemblages, and have more power to control and shape them than they may recognise. The migration research community has a powerful role to play in shaping academic perceptions of how big data should be used in the field of mobility studies, and a unique awareness of the likely misuses of such data.

The ongoing use and sharing of geocoded mobile data presents a strong case for a new debate about research ethics with regard to human mobility, as well as the development of new forms of arbitration and ethical control. As access to data increases, the potential for ethical conflicts grows: people’s right to freedom of movement and the freedom to escape danger may clash with concerns over disease transmission, overcrowding, or strain on receiving areas. In a best-case scenario, what MIT data expert Alex Pentland has termed the ‘god’s eye view’ may enable a timely and appropriate response from authorities without harming data subjects. In a worst-case scenario, however, restriction or harm may occur to those who are moving. In order to achieve a balance between the right to invisibility and the right to be seen, a better system than self-regulation may need to be established for both corporations and researchers.

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How to cite this blog post (Harvard style):

Taylor L (2014) No Place to Hide? The Ethics and Analytics of Tracking Mobility Using Mobile Phone Data. Available at: (Accessed [date]).