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Lundi 20 novembre 2017
Régulation et environnement | 12:00-14:00
Salle R2-01, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
DUSO Tomaso (DIW (Berlin) ) : The Effect of Retail Mergers on Prices and Variety : An Ex-post Evaluation
Co-authors : ARGENTESI Elena, BUCCIROSSI Paolo, CERVONE Robert, MARRAZZO Alessia
Résumé
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Astract We use an original dataset on Dutch supermarkets to assess the effect of a merger that was conditionally approved by the Dutch Competition Authority (ACM) on prices and on the depth of assortment. We adopt a difference-in-differences strategy that exploits local variation in the merger’s effects and we further control for selection on observables when defining our control group. We find that the merger did not affect individual products’ prices but it led the merging parties to reposition their assortment and increase average category prices. While the low-quality target stores reduced the depth of their assortment when in direct competition with the acquirer’s stores, the latter increased their product variety. By analyzing the effect of the merger on category prices, we find that the target most likely dropped high price products, while the acquirer added more of them. These findings suggests that the merging firms reposition their product offerings in order to avoid cannibalization and lessen local competition. We further show that other dimensions of heterogeneity such as market concentration, whether a divestiture was imposed, and the re-branding strategy of the target stores are important to explain the post-merger dynamics. A simple theoretical model of local-market assortment competition explains most of our findings.
Roy | 17:00-18:30
Salle R1-09, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
ESPONDA Ignacio (UC Santa Barbara ) : Equilibrium in Bayesian Markov Decision Processes
Co-authors : POUZO Demian
Résumé
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Abstract : We provide an equilibrium framework for modeling the behavior of an agent who holds a simplified view of a dynamic optimization problem. The agent faces a Markov Decision Process, where a transition probability function determines the evolution of a state variable as a function of the previous state and the agent’s action. The agent is uncertain about the true transition function and has a prior over a set of possible transition functions ; this set reflects the agent’s (possibly simplified) view of her environment and may not contain the true function. We define an equilibrium concept and provide conditions under which it characterizes steady-state behavior when the agent updates her beliefs using Bayes’ rule. Unlike the case for static environments, however, an equilibrium approach for the dynamic setting cannot be used to characterize those steady states where the agent perceives that learning is incomplete. Two key features of our approach is that it distinguishes between the agent’s simplified model and the true primitives and that the agent’s belief is determined endogenously in equilibrium.
- Mardi 21 novembre 2017
Economie appliquée | 12:30-13:30
Salle R1-09, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
ASSOUAD Lydia (PSE) : Measuring lnequality in the Middle East 1990-2016 : The World’s Most Unequal Region ?
Co-authors : ALVAREDO Facundo ; PIKETTY Thomas
Résumé
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In this paper we combine household surveys, national accounts, income tax data and wealth data in order to estimate the level and evolution of income concentration in the Middle East for the period 1990-2016. According to our benchmark series, the Middle East appears to be the most unequal region in the world, with a top decile income share as large as 61%, as compared to 36% in Western Europe, 47% in the USA and 55% in Brazil. This is due both to enormous inequality between countries (particularly between oil-rich and population-rich countries) and to large inequality within countries (which we probably under-estimate, given the limited access to proper fiscal data). We stress the importance of increasing transparency on income and wealth in the Middle East, as well as the need to develop mechanisms of regional redistribution and investment
- Texte intégral [pdf]
Trade | 14:45-16:15
ScPo, 28 rue des Saints Pères, 75007 Paris, salle H405
MANOVA Kalina (Oxford) : *The Origins of Firm Heterogeneity : A Production Network Approach
Co-authors : BERNARD A. (Dartmouth Tuck), DHYNE E. (NBB), MOXNES A. (Oslo), and MAGERMAN G. (ECARES)
Résumé
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This paper quantifies the origins of firm size heterogeneity when firms are interconnected in a production network. We document new stylized facts about the universe of buyer-supplier relationships among all firms in Belgium during 2002-2014. These facts motivate a model in which firms buy inputs from upstream suppliers and sell to downstream buyers and final demand. Firms can be large not only because they have high production capability (i.e. productivity or product quality), but also because they interact with more, better and larger buyers and suppliers, and because they are better matched to their buyers and suppliers. The model delivers an exact decomposition of firm size into supply an demand margins with firm, buyer/supplier and match components. We establish three empirical results. First, demand factors explain 81% of firm size heterogeneity, while supply factors only 19%. Second, nearly all the variation on the demand side (99%) is driven by sales to other firms rather than final demand. By contrast, 88% of the variation on the supply side reflects heterogeneity in own production capability and 12% comes from input suppliers. Third, the extensive margin of the production network dominates the intensive margin. Most of the variance in the network demand and network supply components of firm size is determined by the number of customers and suppliers, rather than their size or capability. Second most important is that firms transact more with partners that are simultaneously more capable and better bilateral matches.
Migration | 17:00-18:15
Salle R1-13, Campus Jourdan, 48 bd Jourdan 75014 Paris
FASANI Francesco (Queen Mary – University of London) : Border Policies and Unauthorized Flows : Evidence from the Refugee Crisis in Europe
Co-authors : FRATTINI Tommaso
PSI PSE | 17:00-18:00
JAROTSCHKIN Alexandra (PSE) : TBD
Mercredi 22 novembre 2017
3e workshop « MAD - Macro/microeconomics of Agriculture and Development »
Abstract
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3rd Workshop « MAD-Macro/microeconomics of Agriculture and Development »
Agriculture, International Trade and Development
22-23 November 2017
Partners : PSE – Paris School of Economics, INRA – GloFoodS Metaprogramme
Histoire économique | 12:30-14:00
Salle R1-11, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
IRIGOIN Alejandra : Standard Error : the problems for economic historians from (mis)taking Spanish American silver as commodity money, 1778 ?1820
Résumé
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An important stream of recent scholarship on issues of global economic history has used silver grains to produce comparable estimates of living standards and market integration in the so called Great Divergence. Considering silver as commodity money they have standardised local prices and wages to the purchasing power of silver in each economy. However, as shown for the case of 1800s China and the US (Irigoin 2009, 2013), silver in the form of the Spanish American peso enjoyed a price in different markets which was relatively independent of its intrinsic value. In other words silver had also a monetary value. Revisiting a high frequency series of the price of silver bullion and specie in Britain through the 18th and early 19th century, the paper first : estimates the premium – and its variation ? that specie had over bullion in the London market and secondly : discusses the implications of using of silver as commodity for comparative purposes. Thirdly and more importantly it also qualifies established interpretations on the economic development of Latin America in the aftermath of its independence from Spain.
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Economie du développement | 16:30-18:00
Salle R2-01, campus Jourdan - 48 bd Jourdan 75014 Paris
BANERJEE Abhijit (MIT/JPAL/PSE) : A Theory of Experimenters-
Co-authors : CHASSANG Sylvain (New York University), MONTERO Sergio (University of Rochester) and SNOWBERG Erik (University of British Columbia)
Résumé
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Abstract This paper proposes a decision-theoretic framework for experiment design. We model experimenters as ambiguity-averse decision-makers, who make trade-o-s between subjective expected performance and robustness. This framework accounts for experimenters’ preference for randomization, and clari-es the circumstances in which randomization is optimal : when the available sample size is large enough or robustness is an important concern. We illustrate the practical value of such a framework by studying the issue of rerandomization. Rerandomization creates a trade-o- between subjective performance and robustness. However, robustness loss grows very slowly with the number of times one randomizes. This argues for rerandomizing in most environments. JEL Classi-cations : C90, D78, D81 Keywords : experiment design, robustness, ambiguity aversion, randomization, rerandomization
- Texte intégral [pdf]
Jeudi 23 novembre 2017
3e workshop « MAD - Macro/microeconomics of Agriculture and Development »
Abstract
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3rd Workshop « MAD-Macro/microeconomics of Agriculture and Development »
Agriculture, International Trade and Development
22-23 November 2017
Partners : PSE – Paris School of Economics, INRA – GloFoodS Metaprogramme
TOM | 12:30-13:30
Salle R1-13, campus Jourdan, 48 bd Jourdan - 75014 Paris
PREVET Antoine (PSE/Université Paris 1)
- Travail et économie publique | 12:30-13:45
GUILLOT Malka (PSE) : Who payed the 75% tax on millionaires ? Optimization of salary incomes and incidence in FranceRésumé
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Using several administrative datasets, I study the impact of temporary tax on top wage income earners, implemented for 2013 and 2014 only and known as the "75% tax above 1 million euros’’. The tax takes the form of a new marginal tax rate of 50% on gross annual salary income above one million euros, which translates into an increase by 10ppt of the overall top marginal tax rate on wage earners from 64% to 74%. About 400 employers paid the tax each year and about 1000 employees were concerned. I document that the incidence of the tax was shared among employers and employees. Yet, the bigger the firm, the more incident on employers it was. Conversely, the smaller the firm, the larger the incidence on wage. Taking advantage of the short term nature of the tax, I show that the tax triggered important optimization response of wage earners, taking the form of time-shifting. I do not see any income-shifting nor any migration response. I study the elasticity of the pre-tax labour income to the net-of-tax rate (1 minus the marginal tax rate) and find an elasticity of 0.3, that I interpret as pure optimization.
Macroéconomie | 15:45-17:00
PSE - 48 boulevard Jourdan, 75014 Paris - salle R1-09
KEISTER Todd (Rutgers University)
Vendredi 24 novembre 2017
Casual Friday | 12:45-13:45
Salle R2-20, Campus Jourdan, 48 boulevard Jourdan, 75014 Paris
TONDINI Alessandro (PSE) : Entrepreneurs as Role Models : Promoting Entrepreneurial Aspirations among High School Students in South Africa
Co-authors : BEHAGHEL Luc (PSE, INRA), MARGOLIS David (PSE, CNRS), PIRAINO Patrizio (UCT)
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