Working papers

Amse working papers has been including the documents issued by Greqam and Sesstim members since 2012. Previous years' working papers includes only the documents issued by Greqam members.
2018-22 Wage Satisfaction and Wage History: How the Present Shapes the Past, Alberto Prati

Although satisfaction measures strongly depend on personal history, the relationship between memory and current well-being is still unclear. This article is dedicated to empirically investigating if current wage satisfaction affects the ability to date past wage changes. We match answers from a French national survey with administrative records, to compare the recalled and actual wage history. Our data support and extend some previous findings from the psychology literature: relatively remote events are recalled as closer in time, while relatively recent events are recalled as further in time. An instrumental variable strategy shows that these effects – respectively known as “forward” and “backward telescoping” – are partially caused by current satisfaction, so that, ceteris paribus, people who are satisfied with their wage tend to date wage cuts as more remote than they actually are. We suggest that this pattern of imperfect recall, which we denote as hedonic telescoping, opens a new perspective in the understanding of the well-known phenomenon of hedonic adaptation.

recall bias, wage satisfaction, wage history, hedonic adaptation, hedonic telescoping
2018-21 Bubble on Real Estate: The Role of Altruism and Fiscal Policy, Lise Clain-Chamosset-Yvrard, Thomas Seegmuller

In this paper, we are interested in the interplay between real estate bubble, aggregate capital accumulation and taxation in an overlapping generations economy with altruistic households. We consider a three-period overlapping generations model with three key elements: altruism, portfolio choice, and financial market imperfections. Households realise different investment decisions in terms of asset at different periods of life, face a binding borrowing constraint and leave bequests to their children. We show that altruism plays a key role on the existence of a productive real estate bubble, i.e. a bubble in real estate raising physical capital stock and aggregate output. The key mechanism relies on the fact that a real estate bubble raises income of retired households. Because of higher bequests, there children are able to invest more in productive capital. Introducing fiscal policy, we show that raising real estate taxation dampens capital accumulation.

bubble, altruism, real estate, credit, overlapping generations
2018-20 Managing Competition on a Two-Sided Platform, Paul Belleflamme, Martin Peitz

On many two-sided platforms, users on one side not only care about user participation and usage levels on the other side, but they also care about participation and usage of fellow users on the same side. Most prominent is the degree of seller competition on a platform catering to buyers and sellers. In this paper, we address how seller competition affects platform pricing, product variety, and the number of platforms that carry trade.

network effects, two-sided markets, platform competition, intermediation, pricing, Imperfect Competition
2018-19 Inclusive Cognitive Hierarchy in Collective Decisions, Yukio Koriyama, Ali Ozkes

We study the implications of structural models of non-equilibrium thinking, in which players best respond while holding heterogeneous beliefs on the cognitive levels of others. We introduce an inclusive cognitive hierarchy model, in which players are capable of projecting the self to others in regard to their cognitive level. The model is tested in a laboratory experiment of collective decision-making, which supports inclusiveness. Our theoretical results show that inclusiveness is a key factor for asymptotic properties of deviations from equilibrium behavior. Asymptotic behavior can be categorized into three distinct types: naïve, Savage rational with inconsistent beliefs, and sophisticated.

collective decision-making, bounded rationality, cognitive hierarchy, information aggregation
2018-18 Secular Stagnation: New Challenges for the Industrialized Countries in the 21st Century, Gilles Dufrenot, Meryem Rhouzlane

This paper attempts to provide an overview of the main challenges facing industrialized in a context of secular stagnation. There is no consensus on the meaning of this concept and various alternative views coexist. We present the key issues in the debates today, accounting for phenomena like the slowdown in factor productivity, liquidity and safety traps, the decline of natural interest rates, the historical downward trend of potential growths and low inflation rates. We provide a bird’s eye survey of the available literature on the causes of secular stagnation from a historical perspective, the symptoms, the main causes as well as some policies proposed to overcome it. We give some illustrations for the United Kingdom, the United States, the euro area and Japan.

secular stagnation, natural interest rates, history, industrialized countries
2018-17 Transborder Ethnic Kin and Local Prosperity: Evidence from Night-Time Light Intensity in Africa, Christophe Muller, Pierre Pecher

Ethnicity often occupies a core role in integrated social, economic, and political development processes, which have mostly been studied within specific countries. Across countries, social and economic development may be supported by political capabilities achieved by ethnic kin abroad, although there is little hard evidence on politico-economic interactions through ethnic networks. We fill this gap by providing the first robust empirical evidence of the substantial effects of political predominance of transborder ethnic kin on local economic development in Africa. This is achieved by specifying and estimating dynamic spatial models of geolocalised luminosity and matching these data with other geolocalised information on geographic, political, and ethnic characteristics. Spatial and ethnic network effects are separately identified and jointly analysed. Not only distinct spatial effects and transborder ethnic effects are exhibited, but also are their complex dynamics and spatial distribution features in terms of local development. The results draw attention to the relevance of a broader international perspective on policies affecting ethnic politics within countries.

local development, ethnic networks, institutions
2018-16 Male Reproductive Health, Fairness and Optimal Policies, Johanna Etner, Natacha Raffin, Thomas Seegmuller

Based on epidemiological evidence, we consider an economy where agents differ through their ability to procreate. Households with impaired fertility may incur health expenditures to increase their chances of parenthood. This health heterogeneity generates welfare inequalities that deserve to be ruled out. We explore three different criteria of social evaluation in the long-run: the utilitarian approach, which considers the well- being of all households, the ex-ante egalitarian criterion, which considers the expected well-being of the worst-off social group, and the ex-post egalitarian one, which only considers the realized well-being of the worst- off. In an overlapping generations model, we propose a set of economic instruments to decentralize each solution. To correct for the externality and inequalities, both a preventive (a taxation of capital) and a redistributive policy are required.

reproductive health, fairness, egalitarianism, optimal policy, OLG model
2018-15 Pollution and Growth: The Role of Pension on the Efficiency of Health and Environmental Policies, Armel Ngami, Thomas Seegmuller

This paper analyses the effect of a pay-as-you-go pension system on the evolution of capital and pollution, and on the efficiency of an environmental versus health policy. In an overlapping generations model (OLG), we introduce endogenous longevity that depends on pollution and health expenditures. Global dynamics may display multiple balanced growth paths (BGP). We show that by discouraging savings, a policy that promotes the pension system enlarges the environmental poverty trap. More surprisingly, the environmental policy has contrasted effects according to the significance of the pension system. If it has a low size, a raise of the environmental policy enlarges the environmental poverty trap and leads to a rise in capital over pollution at the highest stationary equilibrium. In contrast, in economies where intergenerational solidarity is well developed, capital over pollution decreases at the highest BGP. In such a case, the environmental policy does not necessarily lead to a better longevity and growth.

longevity, environment, Health, pension system, growth, Pollution
2018-14 International Credit Markets and Global Business Cycles, Patrick A. Pintus, Yi Wen, Xiaochuan Xing

This paper stresses a new channel through which global financial linkages contribute to the co-movement in economic activity across countries. We show in a two-country setting with borrowing constraints that international credit markets are subject to self-fulfilling variations in the world real interest rate. Those expectation-driven changes in the borrowing cost in turn act as global shocks that induce strong cross-country co-movements in both financial and real variables (such as asset prices, GDP, consumption, investment and employment). When firms around the world benefit from unexpectedly low debt repayments, they borrow and invest more, which leads to excessive supply of collateral and of loanable funds at a low interest rate, thus fueling a boom in both home and abroad. As a consequence, business cycles are synchronized internationally. Such a stylized model thus offers one way to rationalize both the existence of a world business-cycle component, documented by recent empirical studies through dynamic factor analysis, and the factor’s intimate link to global financial markets.

world interest rate, international co-movement, self-fulfilling equilibria
2018-13 Geographic Environmental Kuznets Curves: The Optimal Growth Linear-Quadratic Case, Raouf Boucekkine, Giorgio Fabbri, Salvatore Federico, Fausto Gozzi

We solve a linear-quadratic model of a spatio-temporal economy using a polluting one-input technology. Space is continuous and heterogenous: locations differ in productivity, nature self-cleaning technology and environmental awareness. The unique link between locations is transboundary pollution which is modelled as a PDE diffusion equation. The spatio-temporal functional is quadratic in local consumption and linear in pollution.  Using a dynamic programming method adapted to our infinite dimensional setting, we solve the associated optimal control problem in closed-form and identify the asymptotic (optimal) spatial distribution of pollution.  We show that optimal emissions will decrease at given location if and only if local productivity is larger than a threshold which depends both on the local pollution absorption capacity and environmental awareness. Furthermore, we numerically explore the relationship between the spatial optimal distributions of production and (asymptotic) pollution in order to uncover possible (geographic) Environmental Kuznets Curve cases.

growth, geography, transboundary pollution, infinite dimensional optimal control problems
2018-12 Group Targeting under Networked Synergies, Mohamed Belhaj, Frédéric Deroïan

A principal targets agents organized in a network of local complementarities, in order to increase the sum of agents' effort. We consider bilateral public contracts à la Segal (1999). The paper shows that the synergies between contracting and non-contracting agents deeply impact optimal contracts: they can lead the principal to contract with a subset of the agents, and to refrain from contracting with central agents.

multi-agent contracting, Network, synergies, aggregate effort, optimal group targeting
2018-11 Business Training and Loan Repayment: Theory and Evidence from Microcredit in France, Renaud Bourlès, Anastasia Cozarenco, Dominique Henriet, Xavier Joutard

Although most Microfinance Institutions (MFIs) invest in non-financial services such as business training, empirical evidence on the impact of training on microborrowers’ performance is at best mixed. We address this issue by accounting for business training allocation and its possible effects on borrowers’ behavior. We first show empirically (using data from a French MFI) that the relationship between business training allocation and borrowers’ risk is complex and non- linear. By taking this into account, we establish a positive effect of business training on the survival time of loans. These results are robust to controlling for the MFI’s selection process. We moreover propose a theoretical explanation for the non-linear relationship between borrowers’ risk and training allocation based on reverse asymmetric information, showing that it can lead to increased MFI outreach.

microcredit, business training, reverse asymmetric information
2018-10 Stochastic Petropolitics: The Dynamics of Institutions in Resource-Dependent Economies, Raouf Boucekkine, Fabien Prieur, Chrysovalantis Vasilakis, Benteng Zou

We provide an analysis of institutional dynamics under uncertainty by means of a stochastic differential game of lobbying with two players (conservatives vs liberals) and three main ingredients. The first one is uncertainty inherent in the institutional process itself. The second considers resource windfalls volatility impact on economic and institutional outcomes. Last but not least, the resource windfall level matters in the relative bargaining power of the players. We compute a unique closed-loop equilibrium with linear feedbacks. We show that the legislative state converges to an invariant distribution. Even more importantly, we demonstrate that the most likely asymptotic legislative state is favorable to the liberals. However, the more volatile resource windfalls, the less liberal is the most likely asymptotic state. Finally, we assess the latter prediction on a database covering 91 countries over the period 1973-2005. We focus on financial liberalization policies. We find that as the resources revenues volatility increases, the financial liberalization index goes down. We also find that this property remains robust across different specifications and sample distinctions.

institutional dynamics, petropolitics, lobbying games, revenue-dependent lobbying power, stochastic dynamic games, stochastic stability
2018-09 Exchange Rate Policy and External Vulnerabilities in Sub-Saharan Africa: Nominal, Real or Mixed Targeting?, Fadia Al Hajj, Gilles Dufrenot, Benjamin Keddad

This paper discusses the theoretical choice of exchange rate anchors in Sub-Saharan African countries that are facing external vulnerabilities. To reduce instability, policymakers choose among promoting external competitiveness using a real anchor, lowering the burden of external debt using a nominal anchor or using a policy mix of both anchors. We observe that these countries tend to adopt mixed anchor policies. We solve a state space model to explain the determinants of and the strategy behind this policy. We find that the choice of policy mix is a two-step strategy: First, authorities choose the degree of nominal exchange rate flexibility according to the velocity of money, trade openness, foreign debt, degree of exchange rate pass-through and exchange rate target zone. Second, authorities seek to stabilize the real exchange rate depending on the degree of trade integration with the rest of world and the degree of foreign exchange interventions. We conclude with regime-switching estimations to provide empirical evidence of how these economic fundamentals influence exchange rate policy in Sub-Saharan Africa.

African countries, exchange rate policy, external vulnerabilities, regime-switching model
2018-08 Household Fuel Use in Rural China, Christophe Muller, Huijie Yan

The household transition from dirty to clean fuels is important because of its economic, health and environment consequences, locally, nationally and globally. In order to study fuel choices, a non-separated farm household model for fuel demands is developed. Then, discrete choice equations of fuel uses, consistent with this theoretical model, are estimated using microeconomic household panel data from rural China.The estimation results support the theoretical approach that implies that the fuel demands depend not only on income, fuel prices, and demand-side socioeconomic factors, as would occur in the standard fuel demand models in the literature, but also on food prices, agricultural assets, and original household and community characteristics that shape the household responses to market failures. Finally, we present a few policy simulations that reveal the complex substitution impact of energy price policies in China.We provide the first evidence on: price sensitivity of fuel stacking, that food prices exert some pressure on the fuel transition, the role of farm work and activity specialization in fuel choices. Policies should incorporate some of the complexity of the non-separated decisions of rural households in this context of market failures. The complex cross-price effects imply that the policy pricing mechanisms should account for all energy types and food prices. Finally, market-based policies should be coupled with policy interventions aimed at increasing the opportunity cost of dirty fuels.

fuel use, China, consumption demand, energy
2018-07 Proximités et Solidarités : de l’État-Providence aux Communs Sociaux, Jacques Garnier, Jean-Benoît Zimmermann

Dans cet article, nous nous intéressons à la coévolution des inégalités sociales, des dispositifs de solidarité et du système économique à travers trois grandes phases durant lesquelles les dispositifs de solidarité ont combiné de manière différenciée deux grandes formes de solidarité, par les proximités (par en bas) vs par l’attribution de droits (par en haut). Avec la globalisation de l'économie et la crise des années 2008 et suivantes, les inégalités sociales se sont accentuées et ont revêtu un aspect spatial marqué, jusqu’à une échelle micro-locale. En nous appuyant sur une approche théorique en termes de proximité et en nous référant aux situations largement évoquées aujourd’hui dans la littérature, nous analysons l’incapacité des politiques publiques à répondre efficacement à cette accentuation par la seule prise en compte de la proximité géographique. De nouvelles solidarités « par le bas » tendent en revanche à apporter des réponses hors de la dualité Etat-marché; elles s’apparentent à de nouvelles formes de communs que nous désignons comme « communs sociaux ». Nous montrons en quoi ces communs se distinguent des modalités anciennes de solidarité communautaire. Nous soulignons enfin à quelles conditions ces communs sont susceptibles de constituer des réponses justes et durables à l’accentuation actuelle des inégalités sociales.

France, inégalités, solidarité, proximité, communs territoriaux, communs sociaux
2018-06 Inside the Engine Room of Digital Platforms: Reviews, Ratings, and Recommendations, Paul Belleflamme, Martin Peitz

The rise and success of digital platforms (such as Airbnb, Amazon, Booking, Expedia, Ebay, and Uber) rely, to a large extent, on their ability to address two major issues. First, to effectively facilitate transactions, platforms need to resolve the problem of trust in the implicit or explicit promises made by the counterparties; they post reviews and ratings to pursue this objective. Second, as platforms operate in marketplaces where information is abundant, they may guide their users towards the transactions that these users may have an interest in; recommender systems are meant to play this role. In this article, we elaborate on review, rating, and recommender systems. In particular, we examine how these systems generate network effects on platforms.

platforms, network effects, ratings, recommender systems, digital economics
2018-05 Mean Growth and Stochastic Stability in Endogenous Growth Models, Raouf Boucekkine, Patrick A. Pintus, Benteng Zou

Under uncertainty, mean growth of, say, wealth is often defined as the growth rate of average wealth, but it can alternatively be defined as the average growth rate of wealth. We argue that stochastic stability points to the latter notion of mean growth as the theoretically relevant one. Our discussion is cast within the class of continuous-time AK-type models subject to geometric Brownian motions. First, stability concepts related to stochastic linear homogenous differential equations are introduced and applied to the canonical AK model. It is readily shown that exponential balanced-growth paths are not robust to uncertainty. In a second application, we evaluate the quantitative implications of adopting the stochastic-stability-related concept of mean growth for the comparative statics of global diversification in the seminal model due to Obstfeld (1994).

endogenous stochastic growth, mean growth, stochastic stability, AK model, global diversification
2018-04 Targeting the Key Player: An Incentive-Based Approach, Mohamed Belhaj, Frédéric Deroïan

We consider a network game with local complementarities. A policymaker, aiming at minimizing or maximizing aggregate effort, contracts with a single agent on the network to trade effort change against transfer. The policymaker has to find the best agent and the optimal contract to offer. Our study shows that for all utilities with linear best-responses, it only takes two statistics about the position of each agent on the network to identify the key player: the Bonacich centrality and a weighted measure of the number of closed walks originating from the agent. We also characterize key players under linear quadratic utilities for various contractual arrangements.

key player, Network, Linear Interaction, incentives, contract, limited budget
2018-03 Tying the Politicians’ Hands: The Optimal Limits to Representative Democracy, Didier Laussel

We study the optimal delegation problem which arises between the median voter (writer of the constitution) and the (future) incumbent politician when not only the state of the world and but also the politician’s type (preferred policy) are the policy-maker’s private information. We show that it is optimal to tie the hands of the politician by imposing him/her both a policy floor and a policy cap and delegating him/her the policy choice only in between. The delegation interval is shown to be the smaller the greater is the uncertainty about the politician’s type. These results apply outside the specific problem to which our model is applied here.

representative democracy, optimal delegation, political uncertainty
2018-02 Optimal Cash Transfers with Distribution Regressions: An Application to Egypt at the Dawn of the XXIst Century, Christophe Muller

Social programmes for poverty alleviation involve eligibility rules and transfer rules that often proxy-means tests. We propose to specify the estimator in connection with the poverty alleviation problem. Three distinct stages emerge from the optimization analysis: the identification of the poor, the ranking of their priorities and the calculus of the optimal transfer amount. These stages are implemented simultaneous by using diverse distribution regression methods to generate fitted-values of living standards plugged into the poverty minimization programme to obtain the transfer amounts. We apply these methods to Egypt in 2013. Recentered Influence Function (RIF) regressions focusing on the poor correspond to the most efficient transfer scheme. Most of the efficiency gain is obtained by making transfer amounts varying across beneficiaries rather than by varying estimation methods. Using RIF regressions instead of quantile regressions delivers only marginal poverty alleviation, although it allows for substantial reduction of the exclusion of the poor.

targeting, poverty, optimizing estimator
2018-01 The Causal Effect of Infrastructure Investments on Income Inequality: Evidence from US States, Emma Hooper, Sanjay Peters, Patrick A. Pintus

Through utilizing US state-level data at annual frequency from 1976 to 2008, this paper documents a causal effect of infrastructure investments, specifically public spending on highways, on income inequality. The number of seats in the US House of Representatives Committee On Appropriations serves as a valid instrument to identify quasi-random variations in state-level spending on highways. When a given state gains an additional committee member, which is rather exogenous, new federal grants are allocated to that state, resulting in the state government slashing its investment expenditures on highways. In other words, a crowding-out effect of federal funding for state investment in highways is at play. The main contribution of this paper is to show that such committee-driven cuts in spending on highways cause an increase in income inequality within a two-year horizon. In addition, we show that wages paid for construction jobs correlate positively and strongly with spending on highways at the state level. This further provides suggestive evidence that the construction sector plays an important role in the transmission channel from a rise in state spending on highways to a reduction in income inequality.

public infrastructure, highways, income inequality, US state panel data, instrument variable