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: Politics & Context (language use). 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 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.

Discrete choice models of labour supply, behavioural microsimulation and the Spanish tax reforms

Abstract: The aim of the present study is to show the potential of behavioural microsimulation models as powerful tools for the ex ante evaluation of public policies. We analyse the impact of recent Spanish income tax reforms upon efficiency and household and social welfare and study the effects of various (basic-income and vital-minimum) flat tax schemes. The analysis is performed using a microsimulation model in which labour supply is explicitly taken into account. Instead of following the traditional continuous approach (Hausman, Labour supply, Aaron and Pechman (eds.), How Taxes Affect Economic Behaviour, The Brooking Institution, Washington, DC, 1981; Econometrica, 53: 1255–1282, 1985; Taxes and labour supply, Auerbach and Feldstein, (eds.), Handbook of Public Economics, North-Holland, Amsterdam, vol. 1, 1979), we estimate the direct utility function employing the methodology proposed by Aaberge et al. (Scand. J. Econ., 97: 635–659, 1995) and Van Soest (J. Hum. Resour., 30: 63–88, 1995). We maintain population heterogeneity by applying a social welfare analysis to the complete sample, rather than merely focusing on the active population. The source of our data is a sample of Spanish individuals in the 1995 wave of the EC Household Panel. We find that the redistribution policies considered have only had a minor impact on economic efficiency but, by contrast, have significantly affected social welfare.

Collusive Market Sharing and Corruption in Procurement

Abstract: This paper investigates links between corruption and collusion in procurement. A first-price multiple-object auction is administered by an agent who has legal discretion to allow for a readjustment of (all) submitted offers before the official opening. The agent may be corrupt, that is, willing to "sell" his decision in exchange for a bribe. Our main result shows that the corrupt agent's incentives to extract rents are closely linked with that of a cartel of bidders. First, collusive bidding conveys value to the agent's decision power. Second, self-interested abuse of discretion to extract rents (corruption) provides a mechanism to enforce collusion. A second result is that package bidding can facilitate collusion. We also find that with corruption, collusion is more likely in auctions where firms are small relative to the market. Our main message to auction designers, competition authorities and criminal courts is that risks of collusion and of corruption must be addressed simultaneously. Some other policy implications for the design of tender procedures are discussed.