School for Advanced Studies in the Social Sciences

About: School for Advanced Studies in the Social Sciences is a facility organization based out in Villejuif, France. It is known for research contribution in the topics: Population & Politics. The organization has 1230 authors who have published 2084 publications receiving 57740 citations. The organization is also known as: Ecole des Hautes Etudes en Sciences Sociales & EHESS.

The simplicity of planar networks

Abstract: Shortest paths are not always simple. In planar networks, they can be very different from those with the smallest number of turns - the simplest paths. The statistical comparison of the lengths of the shortest and simplest paths provides a non trivial and non local information about the spatial organization of these graphs. We define the simplicity index as the average ratio of these lengths and the simplicity profile characterizes the simplicity at different scales. We measure these metrics on artificial (roads, highways, railways) and natural networks (leaves, slime mould, insect wings) and show that there are fundamental differences in the organization of urban and biological systems, related to their function, navigation or distribution: straight lines are organized hierarchically in biological cases, and have random lengths and locations in urban systems. In the case of time evolving networks, the simplicity is able to reveal important structural changes during their evolution.

Geometrical Optical Illusion via Sub-Riemannian Geodesics in the Roto-Translation Group

Abstract: We present a neuro-mathematical model for geometrical optical illusions (GOIs), a class of illusory phenomena that consists in a mismatch of geometrical properties of the visual stimulus and its associated percept. They take place in the visual areas V1/V2 whose functional architecture have been modelled in previous works by Citti and Sarti as a Lie group equipped with a sub-Riemannian (SR) metric. Here we extend their model proposing that the metric responsible for the cortical connectivity is modulated by the modelled neuro-physiological response of simple cells to the visual stimulus, hence providing a more biologically plausible model that takes into account a presence of visual stimulus. Illusory contours in our model are described as geodesics in the new metric. The model is confirmed by numerical simulations, where we compute the geodesics via SR-Fast Marching.

The port-city in the fields: investigating an improper urbanity in mid-nineteenth-century Cyprus

Abstract: Among the many locations that the late Ottoman Mediterranean offers for consideration to historians of port-cities, the Cypriot city of Larnaca/Tuzla, with its trade station of Scala/Iskele, is a perplexing case-study. Barely larger than a borough in size, it seems it was absorbed in its countryside confines – not only economically speaking (as was the case with many other hinterlands), but also with regard to the use of cross-border legal notions and the establishment of complex social solidarities. Ottoman and consular archives shed light on the range of these landholding, money-lending and networking operations, while allowing us to analyse their wording and phrasing. As a result, one gains insight into the multilayered semantics and pragmatics of an unsettling urbanity.

A meta-analysis of infants' word-form recognition.

Abstract: Recognizing word forms is an important step on infants' way toward mastering their native language. The present study takes a meta-analytic approach to assess overarching questions on the literature of early word-form recognition. Specifically, we investigated the extent to which there is cross-linguistic evidence for an early recognition lexicon, and how it may be influenced by infant age, language background, and familiarity of the selected stimuli (approximated by parent-reported word knowledge). Our meta-analysis-with open data access on metalab.stanford.edu-was based on 32 experiments in 16 different published or unpublished studies on infants 5-15 months of age. We found an overall significant effect of word-form familiarity on infants' responses. This effect increased with age and was higher for infants learning Romance languages than other languages. We further found that younger, but not older, infants showed higher effect sizes for more familiar word lists. These insights should help researchers plan future studies on word-form recognition.

Prevention Incentives in Long-Term Insurance Contracts

Abstract: Long-term insurance contracts are widespread, particularly in public health and the labor market. Such contracts typically involve monthly or annual premia which are related to the insured’s risk profile, where a given profile might change based on observed outcomes which depend on the insured’s prevention efforts. The aim of this paper is to analyze the latter relationship. In a two-period optimal insurance contract in which the insured’s risk profile is partly governed by the effort he puts on prevention, we find that both the insured’s risk aversion and prudence play a crucial role. If absolute prudence is greater than twice absolute risk aversion, moral hazard justifies setting a higher premium in the first period but also greater premium discrimination in the second period. For specific utility functions, moreover, an increase in the gap between prudence and risk aversion increases the initial premium and the subsequent premium discrimination. These results provide insights on the tradeoffs between long-term insurance and the incentives for primary prevention arising from risk classification, as well as between inter- and intra-generational insurance.