Rapid advancements in machine learning techniques allow mass surveillance to be applied on larger scales and utilize more and more personal data. These developments demand reconsideration of the privacy-security dilemma, which describes the tradeoffs between national security interests and individual privacy concerns. By investigating mass surveillance techniques that use bulk data collection and machine learning algorithms, we show why these methods are unlikely to pinpoint terrorists in order to prevent attacks. The diverse characteristics of terrorist attacks—especially when considering lone-wolf terrorism—lead (...) to irregular and isolated footprints. The irregularity of data affects the accuracy of machine learning algorithms and the mass surveillance that depends on them which can be explained by three kinds of known problems encountered in machine learning theory: class imbalance, the curse of dimensionality, and spurious correlations. Proponents of mass surveillance often invoke the distinction between collecting data and metadata, in which the latter is understood as a lesser breach of privacy. Their arguments commonly overlook the ambiguity in the definitions of data and metadata and ignore the ability of machine learning techniques to infer the former from the latter. Given the sparsity of datasets used for machine learning in counterterrorism and the privacy risks attendant with bulk data collection, policymakers and other relevant stakeholders should critically re-evaluate the likelihood of success of the algorithms and the collection of data on which they depend. (shrink)

"First published by Oxford University Press, 1916."--Title page verso.

We propose and test a model of loyalty in games. Players can mutually maintain loyalty by working towards a common goal that is pareto-superior to any Nash equilibrium without it. Loyalty imposes a psychological cost on defecting in an ongoing cooperation, which is thus sustained. We distinguish loyalty from reciprocity and explain how it complements guilt aversion with two dynamic games from a field experiment conducted in a Pakistani factory. The evidence supports the validity of loyalty, which has a stronger (...) effect within than between groups. (shrink)