Cascades of Coverage: Dynamics of Media Attention to Social Movement Organizations

Gaining attention in the mass media is a key goal of many social movement organizations (SMOs). The dominant explanation of media attention to SMOs is that the media act like a filter, selecting some types of SMOs and events for attention, and ignoring others based on characteristics of these SMOs, events, and their political environment. In contrast to this “bias model,” I argue that some media attention to SMOs is characterized by positive feedback, or rich-get-richer processes: past media attention increases the likelihood of future media attention through its effect on the SMO and on other media outlets. Like other positive feedback systems, media attention can be path dependent, is routinely punctuated by large cascades of attention to previously obscure SMOs, and can be contingent on “accidents” of history: at critical junctures, individuals, organizations, and events have the potential to radically impact the extent of media attention to their movements and organizations. Media attention to SMOs can also become decoupled from the types of events that initially sparked their media attention, becoming spokes-organizations for their movements and receiving media attention for events and stories that they themselves are not involved. In support of this theory, I first show that media attention is, similar to other positive feedback processes, power-law distributed across SMOs using two national (US) data sets. I then illustrate the process of positive feedback in media attention through a case study of the Black Panther Party's rise to prominence in media attention

Model based safety analysis for an Unmanned Aerial System

This paper aims at describing safety architectures of autonomous systems by using Event-B formal method. The autonomous systems combine various activities which can be organised in layers. The Event-B formalism well supports the rigorous design of this kind of systems. Its refinement mechanism allows a progressive modelling by checking the correctness and the relevance of the models by discharging proof obligations. The application of the Event-B method within the framework of layered architecture specification enables the emergence of desired global properties with relation to layer interactions. The safety objectives are derived in each layer and they involve static and dynamic properties such as an independence property, a redundant property or a sequential property. The originality of our approach is to consider a refinement process between two layers in which the abstract model is the model of the lower layer. In our modelling, we distinguish nominal behaviour and abnormal behaviour in order to well establish failure propagation in our architecture

The Marketing of Closed-End Fund IPOs

This study investigates a well-documented enigma in the finance literature, the aftermarket behavior of closed-end fund initial public offerings (IPOs). Many models with rational agents attribute the underpricing of industrial IPOs to information asymmetry between the IPO issues and the investing public. Since closed-end funds typically do not have pre-existing assets or proprietary rights, there is little information asymmetry about their asset valuation. Consequently, these models suggest that closed-end funds should exhibit less underpricing than industrial IPOs. However, information asymmetry theories cannot explain why closed-end funds are successfully brought to market overpriced. Specifically, closed-end funds are overpriced at issue relative to their net asset values (NAVs) due to substantial underwriting fees that average approximately 8% of total issue size. The study investigates these anomalies and describes regulatory and institutional mechanisms that contribute to the pattern of aftermarket returns. The authors perform an intraday analysis of aftermarket trades and quotes in the first 100 days of trading. They find that underwriting arrangements, identified during discussions with underwriters, help to explain not only the their primary observations, but also several unusual patterns in the transactions data. The authors show that the vast majority of volume in the first four weeks of trading is seller-initiated. Since short selling is not possible during this time period, the selling imbalance confirms the presence of flippers. However, these imbalances do not immediately translate into price declines. As the number of issues that are stabilized declines over time, the proportion of issues trading at unencumbered, market-determined prices increases. The authors also provide evidence that underwriters manage the cost of stabilizing by creating a net short position in the number of shares issued during the pre-market. Selling imbalance in the first few trading days has predictive power for the timing of subsequent price decline: the faster the short position is covered through stabilizing purchases, the sooner the price drops. Funds that exercise the over-allotment option experience longer stabilization periods. The authors document that seller-initiated trades are both larger and more profitable than buyer-initiated trades in the after market period. Small investors who buy shares in the aftermarket engage in open market transactions that they believe are at unencumbered prices. The authors believe that their findings support a marketing hypothesis for closed-end fund IPOs. To protect their reputation and improve the likelihood of a successful offer, lead underwriters promise to stabilize prices in the aftermarket, essentially granting free put options with a strike price equal to the offer price. The stabilization bid provides the opportunity for some syndicate members to sell large blocks to flippers during the pre-issue period. The number and size of sell orders in the first few days of trading show that a sizable number of these traders exercise this options and flip their shares back to the syndicate. The size of the trades suggest that they are small, retail customers. The legality of this scenario appears to be within the guidelines of current securities regulation The authors speculate that flippers are wiling to participate because of other inducements they receive through their ongoing relationships with underwriters. On the cost side, underwriters may incur significant costs from flipping and protracted stabilization. However, the cost of stabilization may well be offset by the benefits of assuring a successful initial distribution. Small investors face substantial information processing costs and may be highly susceptible to "marketing" tactics. The authors believe their findings raise questions about the adequacy of current disclosure rules for IPOs, and the propriety of securities regulation that permit short term stabilization in closed-end fund IPO aftermarkets. They also suggest that similar patterns of selling pressure, price stabilization, and asymmetric behavior between large and small trades may be found in two other securities - master limited partnerships and real estate investment trusts.

Making a National Crime: The Transformation of US Lynching Politics 1883-1930

Between the Post-Civil War Reconstruction era and stretching into the beginning of the Civil Rights era, a dramatic shift occurred in the public representations of lynching. Lynching was originally framed as a form of rough justice and popular sovereignty—a necessary response to the heinous crimes of blacks and slow courts. But, over this period, roughly 1883-1930, lynching came to be understood as a form of brutality, anarchy, and “barbarism”. This dissertation addresses the causes and consequences of the changing meanings of lynching. I argue that lynching was increasingly criticized as lynch mobs victimized people from outside of the usual black Southern victims, and thus expanded the scope of anti-lynching politics.Doctor of Philosoph

Avalanches of Attention: Positive Feedback in Media Coverage of Social Movement Organizations

I present a positive feedback model to explain why media attention to SMOs is so unequal, volatile and unpredictable. Receiving some degree of media attention helps groups to receive still more--a cumulative advantage, or rich-get-richer, process. The model presents two empirically verifiable implications: (1) levels of media attention will be power-law distributed across SMOs and (2) coverage dynamics will be path-dependent and thus potentially sensitive to small events early in organization histories. Using new methodology from statistical physics I show that media attention is indeed power-law distributed within three large datasets describing counts of media stories to SMOs spanning multiple movements, time periods and media outlets. I then explore the path dependent nature of media coverage with a comparative analysis of the Black Panther Party and the Revolutionary Action Movement. The two groups were initially very similar, the Black Panthers, however, were able to turn early media attention into further media attention, while the Revolutionary Action Movement was not, eventually resulting in a roughly eighty fold difference in levels of media attention between the two groups. Jointly, the quantitative and qualitative results provide broad support for the positive feedback model.Master of Art

Analyse de sécurité de systèmes autonomes: formalisation et évaluation en Event-B

Cet article présente une partie de l'étude d'architectures de sécurité de systèmes autonomes s'appuyant sur l'utilisation de la méthode formelle Event-B. Le formalisme Event-B supporte bien la conception rigoureuse de ces systèmes qui combinent diverses activités que l'on peut structurer en couches. Sa technique de raffinement permet une modélisation progressive en vérifiant la correction et la pertinence des modèles par décharge de preuves. L'application de la méthode Event-B dans le cadre de la spécification d'architectures en couches garantit l'émergence de propriétés globales attendues, telles que les propriétés de sécurité, lorsque l'on s'assure du respect de propriétés au niveau des relations entre les couches. Cet article se situe au début de cette nouvelle étude. Il présente les principes de la modélisation Event-B d'un système de contrôle de drone simplifié. Il caractérise le concept d'architecture en couches utilisée pour cette modélisation. Il décrit ensuite une première modélisation d'une couche avant de conclure sur l'intérêt de cette modélisation pour la validation de systèmes autonomes par rapport aux objectifs de sécurité fixés

Group Threat and Policy Change: The Spatial Dynamics of Prohibition Politics, 1890–1919

The authors argue that group threat is a key driver of the adoption of new and controversial policies. Conceptualizing threat in spatial terms, they argue that group threat is activated through the joint occurrence of (1) proximity to threatening groups and (2) the population density of threatened groups. By analyzing the adoption of county and state "dry laws" banning alcohol from 1890 to 1919, they first show that prohibition victories were driven by the relative strength of supportive constituencies such as native whites and rural residents, vis-à-vis opponents such as Irish, Italian, or German immigrants or Catholics. Second, they show that threat contributed to prohibition victories: counties bordering large immigrant or urban populations, which did not themselves contain similar populations, were more likely to adopt dry laws. Threat arises primarily from interactions between spatially proximate units at the local level, and therefore higher-level policy change is not reducible to the variables driving local policy

Model based system assessment: formalisation et évaluation de systèmes autonomes en Event-B

Cet article vise à décrire une architecture de sécurité de systèmes autonomes à l’aide de la méthode formelle Event-B. Le formalisme Event-B supporte une conception rigoureuse de ces systèmes. La technique de raffinement permet une modélisation progressive en vérifiant la correction et la pertinence des modèles par décharge de preuves. L’application de la méthode Event-B présente un intérêt dans la formalisation des relations entre couches qui assurent la cohérence d’un fonctionnement sûr ainsi que le respect des exigences de sécurité concernées par notre analyse. Par conséquent, la modélisation autour de ces relations fait apparaître en permanence un comportement nominal associé à des comportements en présence de fautes sous l’hypothèse d’une architecture intégrant des mécanismes de tolérance aux fautes

Governance traditions and narratives of public sector reform in contemporary France.

This article explores the basic traditions of governance in contemporary France and the narratives of public sector reform associated with them. It should be stressed right from the outset that this article does not aim to describe the set of public sector reforms that have been implemented in France in the last ten years or so. Instead, the aim is to demonstrate the similarities and differences between the narratives of the left and the right with regard to these reforms and to show how these narratives help to explain the types of reform that have been enacted. The basic argument is that there is a certain commonality to both the left and the right with regard to their narratives of public sector reform. At the same time, though, there are differences of emphasis both within each tradition and between the two main traditions themselves. Except where indicated, all translations are the author's own