Showing papers by "School for Advanced Studies in the Social Sciences published in 2015"

From mobile phone data to the spatial structure of cities

Abstract: Pervasive infrastructures, such as cell phone networks, enable to capture large amounts of human behavioral data but also provide information about the structure of cities and their dynamical properties. In this article, we focus on these last aspects by studying phone data recorded during 55 days in 31 Spanish cities. We first define an urban dilatation index which measures how the average distance between individuals evolves during the day, allowing us to highlight different types of city structure. We then focus on hotspots, the most crowded places in the city. We propose a parameter free method to detect them and to test the robustness of our results. The number of these hotspots scales sublinearly with the population size, a result in agreement with previous theoretical arguments and measures on employment datasets. We study the lifetime of these hotspots and show in particular that the hierarchy of permanent ones, which constitute the 'heart' of the city, is very stable whatever the size of the city. The spatial structure of these hotspots is also of interest and allows us to distinguish different categories of cities, from monocentric and "segregated" where the spatial distribution is very dependent on land use, to polycentric where the spatial mixing between land uses is much more important. These results point towards the possibility of a new, quantitative classification of cities using high resolution spatio-temporal data.

Financialisation of Valuation

Abstract: This article shows that forms of analysis and calculation specific to finance are spreading, and changing valuation processes in various social settings. This perspective is used to contribute to the study of the recent transformations of capitalism, as financialisation is usually seen as marking the past three decades. After defining what is meant by “financialised valuation,” different examples are discussed. Recent developments concerning the valuation of assets in accounting standards and credit risk in banking regulations are used to suggest that colonisation of financial activities by financialised valuations is taking place. Other changes, concerning the valuation of social or cultural activities and environmental issues are also highlighted in order to support the hypothesis of a parallel colonisation of non-financial activities by financialised valuations. Specifically, the language of finance appears to gradually being incorporated into public policies, especially in Europe—and this trend seems to have gathered pace since the 2000s. Some interpretations are proposed to understand why public policies are seemingly increasingly reliant on financialised valuations.

Influence of sociodemographic characteristics on human mobility

Abstract: Human mobility has been traditionally studied using surveys that deliver snapshots of population displacement patterns. The growing accessibility to ICT information from portable digital media has recently opened the possibility of exploring human behavior at high spatio-temporal resolutions. Mobile phone records, geolocated tweets, check-ins from Foursquare or geotagged photos, have contributed to this purpose at different scales, from cities to countries, in different world areas. Many previous works lacked, however, details on the individuals’ attributes such as age or gender. In this work, we analyze credit-card records from Barcelona and Madrid and by examining the geolocated credit-card transactions of individuals living in the two provinces, we find that the mobility patterns vary according to gender, age and occupation. Differences in distance traveled and travel purpose are observed between younger and older people, but, curiously, either between males and females of similar age. While mobility displays some generic features, here we show that sociodemographic characteristics play a relevant role and must be taken into account for mobility and epidemiological modelization.

Multiplex networks in metropolitan areas: generic features and local effects

Abstract: Most large cities are spanned by more than one transportation system. These different modes of transport have usually been studied separately: it is however important to understand the impact on urban systems of coupling different modes and we report in this paper an empirical analysis of the coupling between the street network and the subway for the two large metropolitan areas of London and New York. We observe a similar behaviour for network quantities related to quickest paths suggesting the existence of generic mechanisms operating beyond the local peculiarities of the specific cities studied. An analysis of the betweenness centrality distribution shows that the introduction of underground networks operate as a decentralizing force creating congestion in places located at the end of underground lines. Also, we find that increasing the speed of subways is not always beneficial and may lead to unwanted uneven spatial distributions of accessibility. In fact, for London—but not for New York—there is an optimal subway speed in terms of global congestion. These results show that it is crucial to consider the full, multimodal, multilayer network aspects of transportation systems in order to understand the behaviour of cities and to avoid possible negative side-effects of urban planning decisions.

Multiplex networks in metropolitan areas: generic features and local effects

Abstract: Most large cities are spanned by more than one transportation system. These different modes of transport have usually been studied separately: it is however important to understand the impact on urban systems of the coupling between them and we report in this paper an empirical analysis of the coupling between the street network and the subway for the two large metropolitan areas of London and New York. We observe a similar behaviour for network quantities related to quickest paths suggesting the existence of generic mechanisms operating beyond the local peculiarities of the specific cities studied. An analysis of the betweenness centrality distribution shows that the introduction of underground networks operate as a decentralising force creating congestions in places located at the end of underground lines. Also, we find that increasing the speed of subways is not always beneficial and may lead to unwanted uneven spatial distributions of accessibility. In fact, for London -- but not for New York -- there is an optimal subway speed in terms of global congestion. These results show that it is crucial to consider the full, multimodal, multi-layer network aspects of transportation systems in order to understand the behaviour of cities and to avoid possible negative side-effects of urban planning decisions.

The constitution of visual perceptual units in the functional architecture of V1

Abstract: In this paper we show that the emergence of perceptual units in V1 can be explained in terms of a physical mechanism of simmetry breaking of the mean field neural equation. We consider a mean field neural model which takes into account the functional architecture of the visual cortex modeled as a group of rotations and translations equipped with a degenerate metric. The model generalizes well known results of Bressloff and Cowan which, in absence of input, accounts for hallucination patterns. The main result of our study consists in showing that in presence of a visual input, the stable eigenmodes of the linearized operator represent perceptual units of the visual stimulus. The result is strictly related to dimensionality reduction and clustering problems.

The Developmental Trajectory of Toddlers' Comprehension of Unfamiliar Regional Accents.

Abstract: Efficient language use involves the capacity to flexibly adjust to varied pronunciations of words. Although children can contend with some accent variability before their second birthday, it is currently unclear when and how this ability reaches its mature state. In a series of five experiments, we examine the developmental trajectory of toddlers’ comprehension of unfamiliar regional accents. Experiments 1 and 2 reveal that Canadian-English-learning 25-month-olds outperform their 20-month-old peers on the recognition of Australian-accented words and that this effect is likely driven by 25-month-olds’ larger vocabulary size. Experiments 3 to 5 subsequently show that 25-month-olds’ recognition of familiar words holds regardless of prior exposure to the speaker or accent. Taken together, these findings suggest that children’s ability to cope with accent variation improves substantially as their vocabulary expands in the second year of life and once it does, children recognize accented words on the fly, even ...

Of ordinariness and citizenship processes

Abstract: This paper explores the relations between ordinariness and citizenship processes along two different lines. It first aims at empirically exploring certain uses of ordinariness as a political category. While it is often used as a depoliticisation tool, the two case studies analysed here underline on the contrary its politicising potential. In a second, briefer, part, it proposes a discussion of the gains to be obtained in citizenship studies, from using ordinariness as a category of analysis. Approaching citizenship processes ‘from the ordinary’ is a fruitful perspective from which the political dimensions of usually unseen or unheard practices and sites can be grasped. What connects the two discussions presented here is the complex and paradoxical relationship the two categories of ordinariness and politics entertain, both empirically and analytically.

On Commitments and Other Uncertainty Reduction Tools in Joint Action

Abstract: In this paper, we evaluate the proposal that a central function of commitments within joint action is to reduce various kinds of uncertainty, and that this accounts for the prevalence of commitments in joint action. While this idea is prima facie attractive, we argue that it faces two serious problems. First, commitments can only reduce uncertainty if they are credible, and accounting for the credibility of commitments proves not to be straightforward. Second, there are many other ways in which uncertainty is commonly reduced within joint actions, which raises the possibility that commitments may be superfluous. Nevertheless, we argue that the existence of these alternative uncertainty reduction processes does not make commitments superfluous after all but, rather, helps to explain how commitments may contribute in various ways to uncertainty reduction.

Tax policy and income inequality in the United States, 1979–2007

Abstract: This paper assesses the effects of U.S. tax policy reforms on inequality over around three decades, from 1979 to 2007. It applies a new method for decomposing changes in government redistribution into (1) a direct policy effect resulting from policy changes and (2) the effects of changing market incomes. Over the period as a whole, the tax policy changes increased income inequality by pushing up the income share of high-income earners (the top 20%). (JEL H23, H31, H53, P16)

Tax Policy and Income Inequality in the United States, 1979-2007

Abstract: This paper assesses the effects of U.S. tax policy reforms on inequality over around three decades, from 1979 to 2007. It applies a new method for decomposing changes in government redistribution into (1) a direct policy effect resulting from policy changes and (2) the effects of changing market incomes. Over the period as a whole, the tax policy changes increased income inequality by pushing up the income share of high-income earners (the top 20%). (JEL H23, H31, H53, P16)

Explanation in Linguistics

Abstract: The aim of the present paper is to understand what the notions of explanation and prediction in contemporary linguistics mean, and to compare various aspects that the notion of explanation encompasses in that domain. The paper is structured around an opposition between three main styles of explanation in linguistics, which I propose to call ‘grammatical’, ‘functional’, and ‘historical’. Most of this paper is a comparison between these different styles of explanations and their relations (Sections 3, 4, 7, and 8). A second, more methodological aspect this paper seeks to clarify concerns the extent to which linguistic explanations can be viewed as predictive, rather than merely descriptive (Sections 2, 5, and 6), and the problem of whether linguistic explanations ought to be causal, rather than noncausal (Section 6). I argue that the notion of prediction is equally applicable in linguistics as in other empirical sciences. The extent to which the computational model of generative syntax can be viewed as providing a causal or psychologically realist model of language is more controversial (Sections 5–9).

Roads and cities of 18th century France

Abstract: The evolution of infrastructure networks such as roads and streets are of utmost importance to understand the evolution of urban systems. However, datasets describing these spatial objects are rare and sparse. The database presented here represents the road network at the french national level described in the historical map of Cassini in the 18th century. The digitization of this historical map is based on a collaborative methodology that we describe in detail. This dataset can be used for a variety of interdisciplinary studies, covering multiple spatial resolutions and ranging from history, geography, urban economics to network science.

Grappling with the Economy of Enrichment

Abstract: In a conversation with Fabian Muniesa from the board of editors of Valuation Studies, Luc Boltanski and Arnaud Esquerre unravelled a few of the distinguishing features of their new work on the sociology of valuation. Combining an updated view on the pragmatics of justification and a more recent preoccupation with the problem of prices, their proposal appears as both a suitable contribution and a timely challenge to current threads in valuation studies. It also interacts in a stimulating fashion with their concomitant analysis of the political atmosphere in France, and more widely of the shift to identity that so vividly informs the critique of capitalism today.

Pragmatic Interpretations of Vague Expressions: Strongest Meaning and Nonmonotonic Consequence

Abstract: Recent experiments have shown that naive speakers find borderline contradictions involving vague predicates acceptable. In Cobreros et al. (Journal of Philosophical Logic, 41, 347–385, 2012a) we proposed a pragmatic explanation of the acceptability of borderline contradictions, building on a three-valued semantics. In a reply, Alxatib et al. (Journal of Philosophical Logic, 42, 619–634, 2013) show, however, that the pragmatic account predicts the wrong interpretations for some examples involving disjunction, and propose as a remedy a semantic analysis instead, based on fuzzy logic. In this paper we provide an explicit global pragmatic interpretation rule, based on a somewhat richer semantics, and show that with its help the problem can be overcome in pragmatics after all. Furthermore, we use this pragmatic interpretation rule to define a new (nonmonotonic) consequence-relation and discuss some of its properties.

Political Violence and Kurds in Turkey: Fragmentations, Mobilizations, Participations & Repertoires

Abstract: The Kurdish conflict is an acknowledged long-standing issue in the Middle East, and the emergence of radical Kurdish nationalist movements in the 20th century played a decisive role in the evolution of political violence. Political Violence and Kurds in Turkey examines how this political violence impacts Kurds in contemporary Turkey, and explores the circumstances that move human beings to violent acts. It looks at the forms political violence takes and in which times and spaces it occurs, as well as the roles played by micro and macro factors. It takes a theoretical approach to violence, as both producer and product of interrelations between many actors, and contextualises this with studies of violence in Kurdish villages and towns. The book evaluates the three levels at which political violence operates; between the state and Kurdish movements, among Kurdish groups and between Kurdish political organizations and Kurdish society, and divides it into its different aspects and processes; fragmentation-segmentation (signifying intra-ethnic struggles between Kurdish actors), mobilization (the course leading the Kurdish movement to armed conflict), participation (the use of violence by individuals) and repertoires (the forms taken by political violence). Offering an in-depth analysis of the dynamics behind political violence and its use amongst Kurds in Turkey, this book will be a key resource for students and scholars of Middle Eastern, Kurdish Studies and Conflict Studies, and offers new understanding and approaches to the study of political violence.

Evaluation as Practical Judgment

Abstract: What does evaluation mean? This paper studies the evaluative process as a practical judgment that links a situation to a set of values in order to decide upon a course of action. In the first part, the article follows Sen’s account of an evaluative process. His critique of the monist, deductive and idealist theory of Rawls leads to a “relational” and “comparative” approach of the evaluation. Incompletedness, comparison, reality and deliberation are the key principles of this methodology. This is close to insights of John Dewey. Nevertheless, Dewey grasps the pragmatic dimension of the process more precisely then Sen. He firstly makes the distinction between prizing and appraisal, valuation and evaluation. And secondly, the singular situation is underlined as a component of any evaluation. Therefore, evaluation requires empirical inquiry and public deliberation. In a third step, the article focuses on the relationship between evaluation and norms in practical judgments. As explained in the paper, norms are close to, but different from, values. As horizons or constrains, norms contribute to the framing of evaluations. In short, evaluation is a complex process linking prizing and appraisal, situated deliberation, values and norms. Any reduction to a single dimension should mislead the practical judgment, as shown on the example of the evaluation of work.

Cortical spatiotemporal dimensionality reduction for visual grouping

Abstract: The visual systems of many mammals, including humans, are able to integrate the geometric information of visual stimuli and perform cognitive tasks at the first stages of the cortical processing. This is thought to be the result of a combination of mechanisms, which include feature extraction at the single cell level and geometric processing by means of cell connectivity. We present a geometric model of such connectivities in the space of detected features associated with spatiotemporal visual stimuli and show how they can be used to obtain low-level object segmentation. The main idea is to define a spectral clustering procedure with anisotropic affinities over data sets consisting of embeddings of the visual stimuli into higher-dimensional spaces. Neural plausibility of the proposed arguments will be discussed.

Adjustment and income distribution

Abstract: This paper presents a structural macro simulation model to quantify the effects of alternative stabilization packages on the distribution of income and wealth. The model combines the explicit microeconomic optimizing behavior characteristic of computable general equilibrium models with asset portfolio behavior of macroeconomic models in Tobin's tradition. In this model there are four main mechanisms by which policy changes affect the distribution of income and wealth. First, changes in factor rewards affect directly household income distribution. Second, household real incomes are affected by changes in their respective cost of living indexes. Third, household real incomes are affected by changes in real returns on financial assets since household incomes include income from financial holdings. Fourth, household wealth distribution is affected by capital gains and losses. Illustrative simulations with the model are carried out for a representative economy subject to the interest rate and terms-of-trade shocks of the early 1980s. The simulations suggest a large adverse impact on the distribution of income of a sharp contractionary package.

Acoustic-phonetic differences between infant- and adult-directed speech: the role of stress and utterance position

Abstract: Previous studies have shown that infant-directed speech (IDS) differs from adult-directed speech (ADS) on a variety of dimensions. The aim of the current study was to investigate whether acoustic differences between IDS and ADS in English are modulated by prosodic structure. We compared vowels across the two registers (IDS, ADS) in both stressed and unstressed syllables, and in both utterance-medial and -final positions. Vowels in target bisyllabic trochees in the speech of twenty mothers of 4- and 11-month-olds were analyzed. While stressed and unstressed vowels differed between IDS and ADS for a measure of F0, and trended in similar directions for vowel peripherality, neither set differed in duration. These profiles held for both utterance-medial and -final words.

To become one with the instrument: The unfolding of a musical topography:

Abstract: The present article advances the notion of musical topography to describe the engagement between a practitioner and the musical instrument, emphasizing its developmental character. From the point of view of semiotic anthropology, it is suggested that the development of such a practical engagement is guided by expressivity, and that the instrument appears not only as an extension of the body, but participates in the generation of a unitary field, where bodily motion, the instrument and the tonal space are intertwined. The development of lived musical practice draws its force from a situated tradition that consists of normative, structural and stylistic elements, and of a constellation of genres and values shaped and reshaped by generations of practitioners. Finally, it is emphasized that the notion of musical topography brings back to musical praxis its long neglected imaginative dimension.

A Socioenvironmental Shale Gas Controversy Scientists’ Public Communications, Social Responsibility and Collective Versus Individual Positions

Abstract: In this case study, we analyze the discourse, practices and representations of a group of scientists who issued public statements about the French shale gas controversy. The reasons they gave for engaging in this process of communication focused on their social responsibility, their collective ad hoc expertise and the neutrality of their position. We also investigated how these scientists actually produced their communications, despite the tensions between individual and collective positions. We discuss how this experience led them to reflect both individually and collectively on their representations of science in society.

Embodied aesthetics: insight from cognitive neuroscience of the performing arts.

Abstract: Echoing the phenomenological tradition in philosophy, recent hypotheses have proposed that aesthetic experiences are grounded in the embodied simulation of the actions, emotions, and corporeal sensations represented in artworks. We refer to these simulative processes as “embodied aesthetics”. Recent investigations in cognitive neuroscience have helped us to explore the mechanisms of complex human experiences and some of them have been specifically dedicated to the study of the neural underpinning of aesthetic experience. Their results have repeatedly suggested that the creation and the perception of artworks activate a set of shared brain mechanisms, especially as far as performing arts (such as music and dance) are concerned. For instance, pleasurable dance may resonate in the spectators’ brain by enhancing the activity in motor-related areas. This evidence points to the universal involvement of a motor resonance mechanism in aesthetic experience. The present chapter will initially explore the general idea of embodiment. We will then describe some studies in the field of performing arts, where the human body is the object of aesthetic stimulation and the subject of the aesthetic experience. We will also describe how embodiment is modulated by different properties of the stimuli, by the performers’ body or by the preference of the observer. Overall, we expect to provide a framework to better understand aesthetic experience from an embodiment perspective, taking into consideration the different factors that interact with these processes, especially as far as the performing arts are concerned.