Strategic Registration of Voters: The Chilean Case

In this paper we investigate how the employment relationship, if it implies transfer of rents, may allow employers to control the voting behavior of their workers and lead to strategic registration of voters. This is feasible when individual voting behavior is observable, as in open ballot elections. More easily controlled voters are more likely registered providing an even larger impact of vote controlling on election results. Making individual vote truly secret (for instance with the adoption of a secret ballot) significantly reduces this control. Moreover, we show that as long as electoral districts are heterogeneous enough, i.e., contain also free voters, any attempt to control votes on the basis of district aggregate results is bound to fail. We test the predictions of the model by examining in detail the effects of the introduction of thesecret ballot in Chile in 1958.

Land Inequality and Conflict Intensity

This paper investigates the impact of land inequality on conflict intensity. A fundamental distinction with the existing literature lies in the nature of inequality under consideration. We investigate how land inequality across landlords only influences the intensity of the fight against a rebel group constituted by landless individuals. We show that conflict intensity is non-monotonic in land inequality. In particular, the most severe conflicts occur for intermediate land inequality levels. Moreover, a Pareto improving transfer of land from the smaller to the larger landlord may exist. --Conflict,Land Redistribution,Inequality

Beyond Divide-and-Rule: Sparking Civil War to Hold on Power

We propose a model where an autocrat rules over an ethnically divided society. The dictator carefully selects the tax rate over the subjects' production and the nation's natural resources to maximize his rent under the threat of a revolution. We show that it may be in the interest of a weak ruler to foster civil strife to enhance his taxing capacity. By exacerbating existing group antagonisms the leader weakens potential opposition, thereby allowing him to increase fiscal pressure. Important stocks of natural resources and an unequal distribution of these resources across ethnic groups makes this strategy more profitable for the ruler.Autocracy, Divide-and-Rule

Effective viscosity of grease ice in linearized gravity waves

Grease ice is an agglomeration of disc-shaped ice crystals, named frazil ice, which forms in turbulent waters of the Polar Oceans and in rivers as well. It has been recognized that the properties of grease ice to damp surface gravity waves could be explained in terms of the effective viscosity of the ice slurry. This paper is devoted to the study of the dynamics of a suspension of disc-shaped particles in a gravity wave field. For dilute suspensions, depending on the strength and frequency of the external wave flow, two orientation regimes of the particles are predicted: a preferential orientation regime with the particles rotating in coherent fashion with the wave field, and a random orientation regime in which the particles oscillate around their initial orientation while diffusing under the effect of Brownian motion. For both motion regimes, the effective viscosity has been derived as a function of the wave frequency, wave amplitude and aspect ratio of the particles. Model predictions have been compared with wave attenuation data in frazil ice layers grown in wave tanks.Comment: 13 pages, 3 eps figures included; one more section on inertia effect

Beyond divide and rule: weak dictators, natural resources and civil conflict

We propose a model where an autocrat rules over an ethnically divided society. The dictator selects the tax rate over domestic production and the nation's natural resources to maximize his rents under the threat of a regime-switching revolution. We show that a weak ruler may let the country plunge in civil war to increase his personal rents. Inter-group fighting weakens potential opposition to the ruler, thereby allowing him to increase fiscal pressure. We show that the presence of natural resources exacerbatesthe incentives of the ruler to promote civil conflict for his own profit, especially if the resources are unequally distributed across ethnic groups. We validate the main predictions of the model using cross-country data over the period 1960-2007, and show that our empirical results are not likely to be driven by omitted observable determinants of civil war incidence or by unobservable country-specific heterogeneity.

Social Conflict, Mafia, and State Capacity

In this paper we study the rise of the Sicilian mafia at the end of the 19th century and its impact on medium-term and long-term economic outcomes, state capacity and political competition. The new hypothesis, which we develop and empirically substantiate, is that the mafia’s expansion was triggered as a response to the rise of socialist peasant movements starting in 1893. Following the very severe drought and agrarian crisis, the Fasci dei Lavoratori spread among Sicilian peasants, who organized to demand better working conditions and higher wages, and landowners turn to the mafia to counter these movements. Exploiting differences in rainfall and drought intensity in 1893 as a source of variation across municipalities, we document a large response of peasant organizations and then the spread of the mafia within Sicily. The pattern we present is robust and does not exist when one focuses on rainfall or drought variation in other years, bolstering the case that this corresponds to a specific causal channel working only in the context of the expansion of these peasant organizations. Using drought intensity in 1893 as an instrument for mafia in the early 1900s, we then investigate the impact of the mafia on educational outcomes in 1900s, long-term political competition and long-term economic outcomes. Our results indicate a sizable impact of the mafia on literacy in the medium-term, and very large impact on political competition, exhibiting itself by municipalities in which mayoral candidates run without opposition, and also long-term impacts on education and income extending into the decades following World War II

The good connections:A Network Analysis of organized crime, patronage, and local elites

So far, the application of network analysis to crime has been limited to the relationships within criminal networks. We build a novel network dataset by encoding information coming from the archive of the Italian Anti-mafia Commission, describing relationships of collusion and exchange of favours between mafia members and the political, economic and social elites in Sicily, the homeland of the Sicilian mafia. We apply network analysis techniques to study the "topological" role of mafia bosses and show that they strategically position themselves in the social network as an interface between the criminal and the legitimate world

Tiny Deep Learning Architectures Enabling Sensor-Near Acoustic Data Processing and Defect Localization

The timely diagnosis of defects at their incipient stage of formation is crucial to extending the life-cycle of technical appliances. This is the case of mechanical-related stress, either due to long aging degradation processes (e.g., corrosion) or in-operation forces (e.g., impact events), which might provoke detrimental damage, such as cracks, disbonding or delaminations, most commonly followed by the release of acoustic energy. The localization of these sources can be successfully fulfilled via adoption of acoustic emission (AE)-based inspection techniques through the computation of the time of arrival (ToA), namely the time at which the induced mechanical wave released at the occurrence of the acoustic event arrives to the acquisition unit. However, the accurate estimation of the ToA may be hampered by poor signal-to-noise ratios (SNRs). In these conditions, standard statistical methods typically fail. In this work, two alternative deep learning methods are proposed for ToA retrieval in processing AE signals, namely a dilated convolutional neural network (DilCNN) and a capsule neural network for ToA (CapsToA). These methods have the additional benefit of being portable on resource-constrained microprocessors. Their performance has been extensively studied on both synthetic and experimental data, focusing on the problem of ToA identification for the case of a metallic plate. Results show that the two methods can achieve localization errors which are up to 70% more precise than those yielded by conventional strategies, even when the SNR is severely compromised (i.e., down to 2 dB). Moreover, DilCNN and CapsNet have been implemented in a tiny machine learning environment and then deployed on microcontroller units, showing a negligible loss of performance with respect to offline realizations

Massive choleperitoneum three months after mini-gastric bypass for morbid obesity: what every emergency surgeon should be prepared to face. A case report.

Background: Surgery for morbid obesity has spread worldwide, to the point that more than half a million people are operated on each year. As a result, significant numbers of people are living with a new anatomical condition. A mini-gastric bypass is a relatively new bariatric procedure that has gained popularity because of its simplicity and efficacy. Leak rate after this procedure is relatively low (on the order of 1.6%), but marginal ulcer of gastrojejunal anastomosis, if undetected, may lead to leak development. No cases of delayed massive choleperitoneum caused by an almost complete disruption of gastrojejunal anastomosis after mini-gastric bypass have yet been described. Case presentation: We describe here the case of a 51-year-old woman who presented at the emergency department three months after a mini-gastric bypass with acute abdomen caused by massive choleperitoneum due to an almost complete disruption of gastrojejunal anastomosis. The patient underwent an emergency conversion to a Roux-en-Y laparoscopic gastric bypass with associated re-gastrectomy. The postoperative period was characterized by fever due to an infected left pleural effusion, which required treatment with chest tube placement. The patient was discharged three weeks after the operation, in good condition. Six-month follow-up was regular. Conclusions: If suspected, the possibility of marginal ulcer should be investigated as soon as possible. When possible, every obese patient who has complications should be referred to a bariatric surgery department, but each emergency surgeon must be aware of these conditions to be able to treat them optimally