Dryland pastoralism has long attracted considerable attention from researchers in diverse fields. However, rigorous formal study is made difficult by the high level of mobility of pastoralists as well as by the sizable spatio-temporal variability of their environment. This article presents a new computational approach for studying mobile pastoralism that overcomes these issues. Combining multi-temporal satellite images and agent-based modeling allows a comprehensive examination of pastoral resource access over a realistic dryland landscape with unpredictable ecological dynamics. The article demonstrates the analytical potential of this approach through its application to mobile pastoralism in northeast Nigeria. Employing more than 100 satellite images of the area, extensive simulations are conducted under a wide array of circumstances, including different land-use constraints. The simulation results reveal complex dependencies of pastoral resource access on these circumstances along with persistent patterns of seasonal land use observed at the macro level.

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provides economic analysis and policy advice with the aim of promoting sustainable and equitable development. The Institute began operations in 1985 in Helsinki, Finland, as the first research and training centre of the United Nations University. Today it is a unique blend of think tank, research institute, and UN agency-providing a range of services from policy advice to governments as well as freely available original research.

In quantitative studies on animal movements and foraging, there has been ongoing debate over the relevance of Lévy walk and related stochastic models to understanding mobility patterns of diverse organisms. In this study, we collected and analyzed a large number of GPS logs that tracked the movements of different livestock species in northwestern Kenya. Statistically principled analysis has only found limited evidence for the scale-free movement patterns of the Lévy walk and its variants, even though most of the tracked movements clearly show super-diffusive behavior within the relevant temporal duration. Instead, the analysis has given strong support to composite exponential distributions (composite Brownian walks) as the best description of livestock movement trajectories in a wide array of parameter settings. Furthermore, this support has become overwhelming and near universal under an alternative criterion for model selection. These results illuminate the multi-scale and multi-modal nature of livestock spatial behavior. They also have broader theoretical and empirical implications for the related literature.

Since the end of the Cold War, the notion of global security, and presumed threats to it, has undergone considerable expansion and diversification. This process has been led by the United Nations Security Council (UNSC), where active deliberations concerning “threat(s) to the peace” have taken place among major international actors. Despite a sizable accumulation of scholarly arguments, however, the defining features of the structure and dynamics of the post-Cold War security discourse remain ambiguous. To address these ambiguities, this study investigates the entire body of Council deliberations over the past three decades. Based on an original dataset consisting of policy statements delivered at the UNSC, the study employs quantitative text analysis tools, including word embedding, to examine how council members have conceived the notion of security threat in terms of the various issues and entities discussed. It shows the security discourse at the UNSC to be highly stratified and reveals the persistent and pervasive influence of terrorism and the proliferation of weapons of mass destruction, which constitute the limited common grounds shared by the Council’s permanent members. These findings caution against the unconstrained use of certain theoretical constructs widely employed in other works, most notably, “securitization” and “interpretative community.”

This article offers a simple computational model of mobile pastoralists. Employing an agent-based modeling (ABM) approach, the model explicitly simulates the movement patterns of pastoralists and computes the resultant natural resource access for a landscape that shows the typically unpredictable dynamics of African rangeland ecology. Extensive simulations reveal a striking level of efficiency in the exploitation of resource endowments that mobile pastoralists can achieve in otherwise inhospitable environments. The simulations also illuminate the serious welfare consequences of the disruption of pastoral mobility under tight land constraints. These quantitative results are consistent with the rich qualitative evidence from the empirical literature on African pastoralism. Moreover, the article reports on several sets of 'policy experiments' that evaluate the effect of rangeland interventions on the mobility and livelihoods of pastoralists. These endeavors will pave the way for empirically richer and more policy-relevant analyses of dryland pastoralism.

Recent methodological advances in quantitative text analysis enable a not only more rigorous, but also more systematic, investigation of the discursive dynamics that are unfolding among various international actors, in comparison with preceding approaches. This study conducts such an investigation in the context of policy deliberations on international peace and security, by performing cutting-edge text analysis on the entire body of meeting records of the Security Council of the United Nations for the past quarter of a century (1994-2019). Focusing on one of the most consequential notions for the council's policy-making, "threat to the peace," this study employs an unsupervised machine learning model, broadly termed "word embedding," to analyze how this notion has been discussed by relevant members of the council, especially its five permanent members, during the period under investigation. Word embedding estimates the semantic relationships among all words found in a given set of documents, by assigning a high-dimensional vector representation to each of these words. In combination with other natural language processing techniques and simple statistical operations, it reveals persistent patterns of cross-national convergence and divergence in security discourse. While these findings are mostly consistent with existing empirical observations on council politics, some are not, including, most notably, a considerable degree of correlation in how to conceive international threats found between the close-knit Western allies in the council and their Russian counterpart. The study also tracks changing conceptions of threats over time, unveiling distinctive aspects of international relations in each period that have strongly affected the evolution of these conceptions.