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Lunch Seminar

Mondays from 12:30 to 13:30
Library, First Floor, Building 081
Ecole Polytechnique, Palaiseau


Contact: Mathias Andre (Nous contacter" href="mailto:Nous contacter">Nous contacter)

June 6th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Nathalie Picard (Université de Cergy-Pontoise, Ecole Polytechnique) will present a joint work with P.A. Chiappori (University of Columbia) and A. de Palma (ENS Cachan, Ecole Polytechnique)

"Couple Residential Location and Spouses Workplaces"

Abstract: The main purpose of this paper is to study the bargaining power of the household members in the context of location decisions. One important side product of our analysis is the computation of the values of time of the man and the woman. The transport literature neglects the bargaining power, wich leads to biased measures of the values of time. We elaborate a new method to provide an unbiased measure of the value of time. More speci.cally, using census data on the Paris Region, we are able to disentangle bargaining power from the values of time of spouses. We show that the age of the women as well as the nationality of the men, play a crucial role in determining bargaining power. 


May 30th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

André De Palma (ENS Cachan, Ecole Polytechnique) 
will present a joint work with Soumyanetra Munsh (Indian Institute of Management, Bangalore :

"Analysis of competition through exertion of effort

Abstract: This paper models competition for scarce resource when de- mand for the resource cannot be restricted through price adjustments. In this case, individuals compete through exertion of eort to obtain the scarce good. The model can be used to analyse eorts put in by individuals to ob- tain better quality goods in various real-life situations, like obtaining seats in congested public transportation vehicles or obtaining admission into elite educational institutes, when the alternative is a good of worse quality, like having to travel while standing or getting admission to a national institute of lesser prestige.  


May 23rd from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Pierre Cahuc
will present a paper coauthored with Olivier Charlot (THEMA Université CERGY-PONTOISE) and Franck Malherbet (Université de Rouen, Ecole Polytechnique, IZA and fRDB) :

"Temporary Jobs and the Excess of Labor Turnover"


May 9th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Idrissa Sibailly will present a paper:
Inducing environnemental innovation in a oligopoly

Abstract : Environmental advances known as "clean technologies" are often developed in a separate industry (the eco-industry) and sold to polluters subject to environmental regulation. This paper analyzes the impact of the regulation stringency on the diffusion of clean technologies in an oligopoly model wherein polluting firms may purchase (a license to) an environmental process innovation (the clean technology) from a monopolistic technology supplier. Alternatively, we consider two incentives-based policies: an emission unit tax and an auctionedpermits system. In both cases, firms base technological choices on the environmental policyand strategic interactions in the product market as well. Contrary to conventional wisdom, our analysis suggests that beyond certain levels, stricter regulations (e.g. higher carbon prices) do not necessarily induce more firms to implement the clean technology. In fact, as the emission unit price increases, so does the price technology suppliers charge for environmental innovation, which discourages some firms from adopting the "clean technologies".


May 2th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Frank Lichtenberg is the Courtney C. Brown Professor of Business at the Columbia Business School. This semester, he is the Alliance Visiting Professor at Ecole Polytechnique where he teaches a course on Economics of Health Care and Pharmaceuticals. 
The Alliance Program is a partnership between Columbia University and three French universities, the Ecole Polytechnique, Sciences Po and the Universite Paris I Pantheon Sorbonne. 

Prof. Frank Lichtenberg will present his work : 
Has medical innovation reduced cancer mortality?

Abstract: I examine the effects of two important types of medical innovationdiagnostic imaging innovation and pharmaceutical innovationand cancer incidence rates on U.S. cancer mortality rates during the period 1996-2006. The outcome measure we use is not subject to lead-time bias, and our measures of medical innovation are based on extensive data on treatments given to large numbers of patients with different types of cancer.  I estimate difference-in-difference models of the age-adjusted cancer mortality rate using longitudinal, annual, cancer-site-level data on over 60 cancer sites. There is a significant inverse relationship between the cancer mortality rate and both lagged imaging innovation and contemporaneous drug innovation, and a significant positive relationship between the cancer mortality rate and the lagged incidence rate. Imaging innovation, drug innovation, and declining incidence jointly explain about three-fourths of the decline in cancer mortality. Only 7% of the mortality decline is attributable to the decline in (lagged) incidence. About one-fourth of the mortality decline is attributable to drug innovation, and 40% of the decline is attributable to (lagged) imaging innovation. Life expectancy at birth may have been increased by almost three months between 1996 and 2006 by the combined effects of cancer imaging and cancer drug innovation. I also provide estimates of the impact of chemotherapy innovation on French cancer mortality rates.


April 11th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Eduardo Perez will present his work :
"Complexity Inflation in Persuasion"

Abstract: This paper addresses a common criticism of certification processes: that they simultaneously generate excessive complexity, insufficient scrutiny and high rates of undue validation. We build a model in which low and high types pool on their choice of complexity. Higher complexity leads to lower scrutiny by the receiver because it makes understanding marginally more costly. When the receiver is biased towards rejection, more complexity leads to more scrutiny and more selectivity by the receiver, and senders simplify their reports in equilibrium. When the receiver is biased towards validation, however, more complexity leads to more scrutiny but also to less selectivity, and we provide sufficient conditions that lead to complexity inflation in equilibrium. 


April 4th from 12h15 to 13h15
in the Economics Departement's library (ground floor) 

Yukio Koriyama will present a joint work with Jean-François Laslier
"Optimal Apportionment"

Abstract: This paper presents an argument in favor of the "degressive proportionality principle" in apportionment problems. The core of the argument is that each individual derives utility from the fact that the collective decision matches her own will with some frequency, with marginal utility being decreasing with respect to this frequency. Then classical utilitarianism at the social level recommends decision rules which exhibit degressive proportionality. Application is done to the case of the 27 states of the European Union.


March 28th from 12h15 to 13h15
in the Economics Departement's library (ground floor) 

Pierre Picard will present a joint work with Jean Pinquet
"Optimal risk financing in large corporations through insurance captives"

Abstract: A captive is an insurance or reinsurance company established by a parent group to finance its own risks. Captives now play a major role in corporate risk management, with more than 5,000 captives worldwide and most large corporations own an insurance captive. This paper focuses attention on the role of captives as a way to pool risks within large corporations with decentralized business units. We show that for reasonable assumptions on cost parameters, reinsurance captives dominate insurance captives. The paper analyses the vertical contractual chain that links business units to "fronters" through insurance contracts, fronters to the reinsurance captive through the cession of risks and the captive to reinsurers through retrocession. The risk cession by fronters to the reinsurance captive trades off the benefits derived from recouped premiums and from the risk sharing advantage of an "umbrella reinsurance policy", against the risks that result from the captive liabilities. The optimal captive scheme depends on the price of coverage in insurance and reinsurance markets and the intensity of the captive activity may thus fluctuate across time.


March 7th from 12h15 to 13h15
in the Economics Departement's library (ground floor) 

Charles Angeluccil (CREST-TSE) will present a joint work with Antonio Russo (TSE) :
"Moral Hazard and Collusion in Hierarchies"

Abstract : We consider a principal-supervisor-agent hierarchy, with a moral hazard problem at the bottom. Information is hard. Supervisor and agent may collude both before and after the unobservable action is taken. Preventing both forms of collusion entails higher expected payments than if only ex-post collusion is present. We also find a tension between deterring both forms of collusion such that it may be optimal to let collusion occur in equilibrium. The results suggest that the principal may prefer hiring a supervisor auditing the agent only after he has taken its action to having him monitor from the outset. Finally, it is never optimal for the principal to delegate authority to the supervisor.


February 14th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Romain de Nijs 
PSE (Ecole des Ponts ParisTech) and CREST (LEI) 
will present a paper :
"Dynamic Price Discrimination in Free Entry Markets"


Abstract: This article analyzes the common marketing practice which consists in offering different prices to different consumers according to their past purchase behavior in oligopoly markets with free entry. I consider a two-period oligopoly market with repeated purchases wherein firms sell differentiated goods. With a fixed number of competitors, price discrimination boosts firms' profits at the expense of consumers. The profitability of price discrimination can increase with the number of competitors and exhibits an inverted U relationship with the degree of product differentiation. Information sharing about customers past purchases histories between firms magnifies the profitability of price discrimination. However, under free entry, price discrimination leads more firms to be active in the market which eventually benefits consumers but harms the welfare.


February 7th from 12h15 to 13h15
in the Economics Departement's library (ground floor)

Christophe Gouel will present a paper:
"Optimal food price stabilisation policy"


Abstract: We propose a framework for designing an optimal food price stabilisation policy. Using a competitive storage model with risk-averse consumers and incomplete markets, we allow government to stabilise food price by carrying public stock and by using state-contingent subsidy to production. The policy rules are designed to maximise intertemporal welfare. The optimal policy under commitment crowds out all private stockholding activity by removing all profit opportunity. It increases both consumer welfare and short-run producer profits. Most welfare gains come from the stabilisation by public storage, the countercyclical subsidy to production contributing little.