Strategic Information Acquisition in Networked Groups with "Informational Spillovers"

This paper develops a model of costly information acquisition by agents who are connected through a network. For a exogenously given network, each agent decides first on information acquisition from his neighbors and then, after processing the information acquired, takes an action. Each agent is concerned about the extent to which other agents align their actions with the underlying state. A new equilibrium notion, which is in the spirit of perfect Bayesian equilibrium, is proposed to analyze information acquisition decisions within networked groups. This equilibrium notion allows each agent to compute, when deciding about information acquisition, the extent to which changes in his information acquisition decision will affect his own perception of future expected payos. Agents anticipate and incorporate such changes in their information acquisition decisions. Both the efficient and the equilibrium information acquisition proles are characterized and the compatibility between them is related to the density of the network.Incomplete Information, Information Acquisition, Communication Networks, Informational Spillovers, Coordination

Notes on the Suboptimality Result by J. D. Geanakoplos and H. M. Polemarchakis (1986)

J. D. Geanakoplos and H. M. Polemarchakis (1986) prove the generic constrained suboptimality of equilibrium allocations in two period economies with incomplete markets. They perturb asset prices at equilibrium when the degree of market incompleteness equals one. However, since prices are not fundamentals that parameterize the economy, a generic result cannot be obtained in such a way. In these notes we provide complete and detailed version of their proof in which the arguments do not depend on the dimension of the market incompleteness and in which utilities and endowments are perturbed.Incomplete Asset Markets, Constrained Suboptimality, Transversality Theory

Monte Barro: an Ostrogothic fortified site in the Alps

This paper is a reassessment of the original publications of the fortified site of Monte Barro, near Lake Como in Italy, excavated by G.P. Brogiolo and L. Castelletti, which studies its role within the Ostrogothic frontier system. The site is located on a mountain, overlooking the Po plain, but it is close enough to the Alpine passes to control the access into Italy. Built and fortified during the Ostrogothic period, the site was destroyed during the period of the Gothic Wars in the mid sixth century. Because of its location, its views and fortifications, it would be possible to think that it was a fort, especially as it fits perfectly into the Ostrogothic Alpine fortifications, but neither its finds, nor the presence of the main building fully support this statement. Above all, the presence of a bronze hanging crown seems to indicate that some sort of Gothic noble or official lived at the site, which may give Monte Barro not necessarily the category of villa or palace, but certainly an important role within the Gothic administration, probably linked to the Alpine fortification

Unwanted entailments of the current EU AML/CFT regime

Dissertation presented as the partial requirement for obtaining a Master's degree in Law and Financial MarketsA presente tese visa investigar, de forma pragmática, a batalha contra o financiamento do terrorismo e o branqueamento de capitais no contexto do quadro europeu existente, bem como algumas das suas repercussões indesejadas. Para atingir esse objetivo, foi dada uma elucidação abrangente de todo o processo. A investigação, a acusação e a punição de todas as formas de enriquecimento ilícito estão atualmente em voga, bem como, sem dúvida, o financiamento do terrorismo. A monitorização das transações recebeu uma ênfase especial porque é a génese de alertas automatizados de atividades invulgares, dentro de um esquema complexo de relatórios. Foi utilizada uma abordagem técnica do instrumento, especialmente para ilustrar os custos de contingência e prudenciais esperados das instituições financeiras. Os determinantes dos fatores de risco num dado contexto também estavam sob escrutínio, bem como a necessidade de transparência num dado sistema. A tese também elucidou a incongruência de questões de aparente interesse público, nomeadamente a prevenção do branqueamento de capitais e financiamento do terrorismo e as suas reflexões negativas na proteção do consumidor e na integração financeira.The current thesis aimed to pragmatically investigate the battle against terrorism financing and money laundering in the context of the existing European framework, as well as some of its unintended repercussions. To achieve that goal, a comprehensive elucidation of the whole process was given. Investigation, prosecution, and punishment of all forms of illicit enrichment are currently in vogue., as well as, undoubtedly, the financing of terrorism. Transaction monitoring was given a special emphasis because it is the genesis of automated alerts of unusual activities, within a complex reporting scheme. A technical approach of the tool was utilized, especially to illustrate the contingency and prudential costs expected of financial institutions. The determinants of risk factors in given context were also under scrutiny, so was the need for transparency in given system. The thesis also elucidated the incongruity of two seemly public interest matters ML-FT prevention and its negative reflections in consumer protection and financial integration

Engineering, Aqueducts, and the Rupture of Knowledge Transmission in the Visigothic Period

The agitated existing debate between traditional historiography and revisionist positions regarding the nature of the so-called “Visigothic” churches derives, fundamentally, from the proposal that a series of techniques and skills were lost during Late Antiquity. In this paper, I would like to add to the debate by introducing the results from my research on the evolution of aqueducts and water supply in the cities of post-Roman Iberia. The evident lack of proper maintenance and structural repairs fits within general patterns of late antique urban transformations such as the declining interest of curiales in public munificence and the crisis of the municipal institution. But added to this we must see a technical and technological disruption between the Roman past and the Visigothic centuries, which becomes evident when compared with the situation in the Umayyad period and parallels similar developments in other technical skills, such as pottery productions. In this context, the aqueduct of Reccopolis stands out as a unique example of brand new hydraulic infrastructure. Considering how unique the circumstances of Reccopolis are (i.e., royal foundation) and the links between the Visigothic monarchy and the Eastern Empire (where engineering skills were preserved), there is also a case to propose the eventual presence of Eastern engineers linked to this main construction project. Overall, I propose a model in which the lack of demand throughout the fifth and sixth centuries, together with the dismantling of the Imperial state apparatus and the disarticulation of the early Roman municipal system (which favored the construction of aqueducts in the first place) caused a fatal disruption in the transmission of engineering knowledge which, by the period of Visigothic state formation, could only be satisfied by tapping into the active networks of engineering training of the East

Generation of articial thermal sources and their characterization by intensity interferometry

The Hanbury Brown and Twiss (HB-T) effect is fundamental to understand the nature of light, with important applications, for instance in ghost imaging. In this work, some coherence properties of the light emitted by an artifificial source were investigated. In particular, the second-order coherence function in time was retrieved under different experimental conditions. The work included the generation of pseudothermal light by using distinct rotating diffusers. The emitters were then characterized by setting an intensity interferometer (also called Hanbury Brown-Twiss interferometer). This procedure allowed to measure the photon bunching, or equivalently whether and how photons were eventually grouped at the detector. The results showed that the variation of the rotation speed of the difuser played a role in the second-order temporal coherence function, particularly when low rotation speeds were considered