Documents de travail

2020-38
Binary Outcomes and Linear Interactions
Vincent Boucher
Yann Bramoullé

Heckman and MaCurdy (1985) first showed that binary outcomes are compatible with linear econometric models of interactions. This key insight was unduly discarded by the literature on the econometrics of games. We consider general models of linear interactions in binary outcomes that nest linear models of peer effects in networks and linear models of entry games. We characterize when these models are well defined. Errors must have a specific discrete structure. We then analyze the models' game-theoretic microfoundations. Under complete information and linear utilities, we characterize the preference shocks under which the linear model of interactions forms a Nash equilibrium of the game. Under incomplete information and independence, we show that the linear model of interactions forms a Bayes-Nash equilibrium if and only if preference shocks are iid and uniformly distributed. We also obtain conditions for uniqueness. Finally, we propose two simple consistent estimators. We revisit the empirical analyses of teenage smoking and peer effects of Lee, Li, and Lin (2014) and of entry into airline markets of Ciliberto and Tamer (2009). Our reanalyses showcase the main interests of the linear framework and suggest that the estimations in these two studies suffer from endogeneity problems.

Mots clés: binary outcomes, linear probability model, peer effects, econometrics of games
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2020-37
Exchange Rates, Stock Prices, and Stock Market Uncertainty
Fatemeh Salimi Namin

While the reference framework for international portfolio choice emphasizes a mean-variance framework, uncovered parity conditions only involve mean stock or bond returns. We propose to augment the empirical specification by using the relative stock market uncertainty of two countries as an extra determinant of their bilateral exchange rate returns. A rise in the relative uncertainty of one stock market will lead capital to flow to the other stock market and generate an appreciation in the currency of the latter. By focusing on the JPY/USD exchange rate returns during the most recent decade (2009-2019) and relying on a nonlinear framework, we provide evidence that the Japanese-US differential stock market uncertainty affects the JPY/USD returns both contemporaneously and with weekly lags. This finding is robust when we control for the stock returns differential and the differential changes in Japanese and US unconventional monetary policy measures.

Mots clés: exchange rate determination, implied volatility, UEP, flight to safety, flight to quality
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2020-36
An Early Assessment of Curfew and Second COVID-19 Lock-down on Virus Propagation in France
Christelle Baunez
Mickael Degoulet
Stéphane Luchini
Patrick A. Pintus
Miriam Teschl

This note provides an early assessment of the reinforced measures to curb the COVID-19 pandemic in France, which include a curfew of selected areas and culminate in a second COVID-19-related lock-down that started on October 30, 2020 and is still ongoing. We analyse the change in virus propagation across age groups and across départements using an acceleration index introduced in Baunez et al. (2020). We find that while the pandemic is still in the acceleration regime, acceleration decreased notably with curfew measures and this more rapidly so for the more vulnerable population group, that is, for people older than 60. Acceleration continued to decline under lock-down, but more so for the active population under 60 than for those above 60. For the youngest population aged 0 to 19, curfew measures did not reduce acceleration but lock-down does. This suggests that if health policies aim at protecting the elderly population generally more at risk to suffer severe consequences from COVID-19, curfew measures may be effective enough. However, looking at the departmental map of France, we find that curfews have not necessarily been imposed in départements where acceleration was the largest.

Mots clés: COVID-19; effects of curfew and lock-down; acceleration index; real-time analysis; France
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2020-35
Tracking the Dynamics and Allocating Tests for COVID-19 in Real-Time: an Acceleration Index with an Application to French Age Groups and Départements
Christelle Baunez
Mickael Degoulet
Stéphane Luchini
Patrick A. Pintus
Miriam Teschl

An acceleration index is proposed as a novel indicator to track the dynamics of the COVID-19 in real-time. Using French data on cases and tests for the period following the first lock-down-from May 13, 2020, onwards-our acceleration index shows that the ongoing pandemic resurgence can be dated to begin around July 7. It uncovers that the pandemic acceleration has been stronger than national average for the [59 − 68] and [69 − 78] age groups since early September, the latter being associated with the strongest acceleration index, as of October 25. In contrast, acceleration among the [19 − 28] age group is the lowest and is about half that of the [69 − 78], as of October 25. In addition, we propose an algorithm to allocate tests among French départements, based on both the acceleration index and the feedback effect of testing. Our acceleration-based allocation differs from the actual distribution over French territories, which is population-based. We argue that both our acceleration index and our allocation algorithm are useful tools to guide public health policies as France enters a second lock-down period with indeterminate duration.

Mots clés: COVID-19; indicator of epidemic dynamics; acceleration Index; real-time Analysis; sub-national allocation of tests; France
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2020-34
Ethical Voting in Heterogenous Groups
Alberto Grillo

Voting in large elections appears to be both ethically motivated and influenced by strategic considerations. One way to capture this interplay postulates a rule-utilitarian calculus, which abstracts away from heterogeneity in the intensity of support (Feddersen and Sandroni 2006, Coate and Conlin 2004). I argue that this approach is unsatisfactory when such heterogeneity is considered, since it implies that idiosyncratic preferences are irrelevant for participation, in contrast to the empirical evidence. A model of Kantian optimizationà la Roemer (2019), based on the maximization of individual utility under a universalization principle, predicts instead differential participation and links ethical motivation to the spatial theory of voting.

Mots clés: voting, turnout, ethical voter, rule-utilitarian, kantian optimization
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2020-33
Growth factors in developed countries: A 1960-2019 growth accounting decomposition
Gilbert Cette
Aurélien Devillard
Vincenzo Spiezia

Using a new and original database, our paper contributes to the growth accounting literature with three original aspects: first, it covers a long period from the early 60's to 2019, just before the COVID-19 crisis; second, it analyses at the country level a large set of economies (30); finally, it singles out the growth contribution of ICTs but also of robots. The original database used in our analysis covers 30 developed countries and the Euro Area over a long period allowing to develop a growth accounting approach from 1960 to 2019. This database is built at the country level. Our growth accounting approach shows that the main drivers of labor productivity growth over the whole 1960-2019 period appear to be TFP, non-ICT and non-robot capital deepening, and education. The overall contribution of ICT capital is found to be small, although we do not estimate its effect on TFP. The contribution of robots to productivity growth through the two channels (capital deepening and TFP) appears to be significant in Germany and Japan in the sub-period 1975-1995, in France and Italy in 1995-2005, and in several Eastern European countries in 2005-2019. Our findings confirm also the slowdown in TFP in most countries from at least 1995 onwards. This slowdown is mainly explained by a decrease of the contributions of the components 'others' in the capital deepening and the TFP productivity channels.

Mots clés: growth, productivity, ICTs, robots
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2020-32
The Environmental Unsustainability of Public Debt: Non-Renewable Resources, Public Finances Stabilization and Growth
Nicolas Clootens
Francesco Magris

This paper introduces a public debt stabilization constraint in an overlapping generation model in which non-renewable resources constitute a necessary input in the production function and belong to agents. It shows that stabilization of public debt at high level (as share of capital) may prevent the existence of a sustainable development path. Public debt thus appears as a threat to sustainable development. It also shows that higher public debt-to-capital ratios (and public expenditures-to-capital ones) are associated with lower growth. Two transmission channels are identified. As usual, public debt crowds out capital accumulation. In addition, public debt tends to increase resource use which reduces the rate of growth. We also show that the economy is characterized by saddle path stability. Finally, we show that the public debt-to-capital ratio may be calibrated to implement the social planner optimal allocation.

Mots clés: non-renewable resources; growth; public finances; overlapping generations
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2020-31
Why are Low-Skilled Workers less Mobile? The Role of Mobility Costs and Spatial Frictions
Benoît Schmutz
Modibo Sidibé
Elie Vidal-Naquet

Workers' propensity to migrate to another local labor market varies a lot by occupation. We use the model developed by ? to quantify the impact of mobility costs and search frictions on this mobility gap. We estimate the model on a matched employer-employee panel dataset describing labor market transitions within and between the 30 largest French cities for two groups at both ends of the occupational spectrum and find that: (i) mobility costs are very comparable in the two groups, so they are three times higher for blue-collar workers relative to their respective expected income; (ii) Depending on employment status, spatial frictions are between 1.5 and 3.5 times higher for blue-collar workers; (iii) Moving subsidies have little (and possibly negative) impact on the mobility gap, contrary to policies targeting spatial frictions.

Mots clés: mobility costs, spatial frictions, migration, local labor markets, occupation
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2020-30
Prudential Regulation in Financial Networks
Mohamed Belhaj
Renaud Bourlès
Frédéric Deroïan

We analyze risk-taking regulation when financial institutions are linked through shareholdings. We model regulation as an upper bound on institutions' default probability, and pin down the corresponding limits on risk-taking as a function of the shareholding network. We show that these limits depend on an original centrality measure that relies on the cross-shareholding network twice: (i) through a risk-sharing effect coming from complementarities in risk-taking and (ii) through a resource effect that creates heterogeneity among institutions. When risk is large, we find that the risk-sharing effect relies on a simple centrality measure: the ratio between Bonacich and self-loop centralities. More generally, we show that an increase in cross-shareholding increases optimal risk-taking through the risk-sharing effect, but that resource effect can be detrimental to some banks. We show how optimal risk-taking levels can be implemented through cash or capital requirements, and analyze complementary interventions through key-player analyses. We finally illustrate our model using real-world financial data and discuss extensions toward including debt-network, correlated investment portfolios and endogenous networks.

Mots clés: financial network, risk-taking, prudential regulation
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2020-29
The Contribution of Residential Segregation to Racial Income Gaps: Evidence from South Africa
Florent Dubois
Christophe Muller

In this paper, we contend that local segregation should be an essential component of the analyzes of the determination of socio-ethnic income gaps. For this, we adopt a thorough distribution decomposition approach, as a general preliminary descriptive step to prospective specific structural analyses. Focusing on the contemporary White/African gap in South Africa, we first complete Mincer wage equations with an Isolation index that reflects the level of segregation in the local area where individuals dwell. Second, we decompose the income gap distribution into detailed composition and structure components. Third, we explore the heterogeneity of segregation effects on wage gaps along three theoretical lines: racial preferences, labor market segmentation, and networks links. Segregation is found to be the main contributor of the structure effect, ahead of education and experience, and to make a sizable contribution to the composition effect. Moreover, segregation is harmful at the bottom of the African income distribution, notably in relation to local informal job-search networks, while it is beneficial at the top of the White income distribution. Only minor influences of racial preferences and labor market segmentation are found. Specific subpopulations are identified that suffer and benefit most from segregation, including for the former, little educated workers in agriculture and mining, often female, immersed in their personal networks. Finally, minimum wage policies are found likely to attenuate most segregation’s noxious mechanisms.

Mots clés: post-apartheid South Africa, generalized decompositions, income distribution, residential segregation
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2020-28
Parents’ Separation: What Is The Effect On Parents’ and Children’s Time Investments?
Hélène Le Forner

This paper investigates the effect of parental separation on children’s allocation of their time and on the time spent with their parents. Based on detailed time-use diaries from the Panel Study of Income Dynamics - Child Development Supplement, I estimate an individual fixedeffects model and find that being in a single-parent family decreases time spent with at least one parent present by 18% of a standard deviation. Time spent with both parents together and alone with the non-custodial parent is greatly affected, but the custodial parent partially compensates for this decrease. The decrease in time spent with at least one parent involved in an activity is, however, not statistically significant. Parents seem to preserve time spent with their children when the child is younger at separation. Children whose parents are more highly educated are also less affected with regard to engaged time if they are in single-mother families. Time spent with a step-parent does not act as a recovery channel ; but time spent with a grandparent increases in single-mother families.

Mots clés: Time-Use; Child’s Time Investments; Parental Time Investment; Family Structure
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2020-27
Bayesian Inference for Distributional Changes: The Effect of Western TV on Wage Inequality and Female Participation in Former East Germany
Edwin Fourrier-Nicolai
Michel Lubrano

This paper investigates the evolution of wage formation in a Mincer model with sample selection for which we develop Bayesian inference and growth incidence and poverty growth curves. We estimate the effect of an exogenous exposure to Western TV broadcasts on labour market participation and wage inequality in East Germany after the German reunification. Using the GSOEP, we find evidences that Western television had significantly increased wage inequality among males while it has significantly affected female labour participation and led the less productive females to drop out from the market, hiding thus a large increase in wage inequality among females.

Mots clés: Bayesian inference, labour market, distributional changes, sample selection, wage inequality
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2020-26
Asset bubble and endogenous labor supply: a clarification
Kathia Bahloul Zekkari
Thomas Seegmuller

This paper analyzes the link between asset bubbles, endogenous labor and capital. The question is whether endogenous labor, per se, can explain a crowding-in effect of the bubble, i.e. higher levels of capital and labor. With respect to the existing literature, our contribution is twofold. First, we explicitly and theoretically derive the conditions to have a crowding-in effect of the bubble. Second, the utility function we consider allows us to show that this result does not require an arbitrarily high elasticity of intertemporal substitution in consumption. Our result still holds for a unit value of this elascticity (Cobb-Douglas utility).

Mots clés: asset bubbles, crowding-in effect, endogenous labor, overlapping generations
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2020-25
Systemic Risk: a Network Approach
Jean-Baptiste Hasse

We propose a new measure of systemic risk based on interconnectedness, defined as the level of direct and indirect links between financial institutions in a correlation-based network. Deriving interconnectedness in terms of risk, we empirically show that within a financial network, indirect links are strengthened during systemic events. The relevance of our measure is illustrated at both local and global levels. Our framework offers policymakers a useful toolbox for exploring the real-time topology of the complex structure of dependencies in financial systems and for measuring the consequences of regulatory decisions.

Mots clés: financial networks, interconnectedness, systemic risk, spillover
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2020-24
Liberté, Egalité, Fraternité... Contaminé? Estimating the impact of French municipal elections on COVID-19 spread in France
Guilhem Cassan
Marc Sangnier

On March 15, about 20, 000, 000 voters cast their vote for the first round of the 2020 French municipal elections. We investigate the extent to which this event contributed to the COVID-19 epidemics in France. To this end, we first predict each département's own dynamics using information up to the election to calibrate a standard logistic model. We then take advantage of electoral turnout differences between départements to distinguish the impact of the election on prediction errors in hospitalizations from that of simultaneously implemented anti-contagion policies. We report a detrimental effect of the election in locations that were at relatively advanced stages of the epidemics by the time of the election. In contrast, we show that the election did not contribute to the epidemics in départements with lower infection levels by March 15. All in all, our estimates suggest that elections accounted for about 4, 000 excess hospitalizations by the end of March, which represents 15% of all hospitalizations by this time. They also suggest that holding elections in June may not be as detrimental.

Mots clés: COVID-19, hospitalizations, electoral turnout, municipal elections, prediction errors
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2020-23
How Family Transfers Crowd-out Social Assistance in Germany
Edwin Fourrier-Nicolai

The non-take-up of social assistance has been receiving increased attention among policy makers in recent years as it would apparently underpin the effectiveness of public intervention in alleviating poverty. We examine whether receipt of private transfers affects the household decision to take-up social assistance in Germany between 2009 and 2011. We exploit the follow-up of households in the SOEP to reconstruct family links and estimate a model of welfare participation with endogenous private transfers and sample selection of the instruments. We find that 20% of the non-take-up rate is due to monetary substitution of private transfers lowering the welfare program costs. However, we find that social assistance is more effective in alleviating poverty and its intensity than private transfers.

Mots clés: welfare participation, private transfers, family networks
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2020-22
Monetary Policies and Destabilizing Carry Trades under Adaptive Learning
cyril Dell'Eva
Eric Girardin
Patrick Pintus

This paper investigates how different monetary policy designs alter the effect of carry trades on a host small open economy. Capital inflows are expansionary, leading the central bank to raise the interest rate, increasing carry trades' returns, and generating further capital inflows (carry trades' vicious circle). This paper shows how monetary authorities can mitigate or suppress this vicious circle, when agents do not have full information about the central bank's objectives. The best way to deal with the destabilizing effect of carry trades is to target both inflation and capital inflows.

Mots clés: capital inflows, carry trades, interest rate differential, vicious circle, inflation targeting
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2020-21
Modeling Joint Lives within Families
Olivier Cabrignac
Arthur Charpentier
Ewen Gallic

Family history is usually seen as a significant factor insurance companies look at when applying for a life insurance policy. Where it is used, family history of cardiovascular diseases, death by cancer, or family history of high blood pressure and diabetes could result in higher premiums or no coverage at all. In this article, we use massive (historical) data to study dependencies between life length within families. If joint life contracts (between a husband and a wife) have been long studied in actuarial literature, little is known about child and parents dependencies. We illustrate those dependencies using 19th century family trees in France, and quantify implications in annuities computations. For parents and children, we observe a modest but significant positive association between life lengths. It yields different estimates for remaining life expectancy, present values of annuities, or whole life insurance guarantee, given information about the parents (such as the number of parents alive). A similar but weaker pattern is observed when using information on grandparents.

Mots clés: annuities; collaborative data; dependence; family history; genealogy; grandparents-grandchildren; information; joint life insurance; parents-children; whole life insurance
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2020-20
Minimum wage and immigrants' participation in the welfare system: evidence from France
Eva Moreno-Galbis

This study examines how minimum wage laws affect the share of immigrants receiving welfare benefits. Minimum wage increases might have larger effects among low-skilled immigrants than among low-skilled natives because, on average, immigrants are less productive. We develop an analytical framework in which a government legislated minimum wage increase promotes a decrease in labor demand and an increase in the earned wage. The net impact on the expected wage is then ambiguous and so is the impact on search effort of unemployed. However, we expect the reduction in labor demand to be more important for immigrants due to their lower productivity. Immigrants remain unemployed and eventually become welfare recipients. Using the French Labor Force Surveys 2003-2016 we exploit the 2006 and 2012 government legislated minimum wage increases and find consistent evidence that a discretionary increase in the minimum wage induces a rise in the share of immigrants receiving welfare benefits which is more important than the rise estimated for natives. This result is driven by low-skilled immigrants and no significant effect arises for high-skilled. Endogeneity issues are addressed through an IV approach.

Mots clés: minimum wage, welfare benefits, immigrants
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2020-19
The Impact of Infrastructure Investments on Income Inequality: Evidence from US States
Emma Hooper
Sanjay Peters
Patrick A. Pintus

Our analysis of US state-level data on an annual frequency, from 1976 to 2008, sheds new light on a plausible causal link between infrastructure investments, namely public spending on highways, and income inequality. This causal relationship is drawn out by using the number of seats in the US House of Representatives Committee on Appropriations (HRCA) as an instrument to identify quasi-random variations in state-level spending on highways. An exogenous pattern which emerges when a state gains an additional member to the HRCA is that it is allocated with new federal grants. This increase in federal transfers for infrastructure financing results in slashing of expenditures on highways and a crowding-out e˙ect of federal funding for state investments on highways. Spending cuts on highways produced by a new HRCA member being attained by a state can unwittingly cause income inequality to rise over a short two-year time horizon. Similar challenges with decentralized development to finance infrastructure via federal transfers to state and sub-national governments may be encountered by other industrially advanced, emerging and low-income developing economies. US data over the mentioned period reveal a strong positive correlation with state spending on highways and wages paid for construction jobs. Suggestive evidence indicates that the construction sector also plays an important role in the transmission channel from a rise in state spending on highways to lowering income inequality, albeit during specific intervals, as opposed to on a long-term basis.

Mots clés: public infrastructure, highways, income inequality, US state panel data, instrument variable
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2020-18
A dynamic theory of spatial externalities
Raouf Boucekkine
Giorgio Fabbri
Salvatore Federico
Fausto Gozzi

In this paper, we revisit the theory of spatial externalities. In particular, we depart in several respects from the important literature studying the fundamental pollution free riding problem uncovered in the associated empirical works. First, instead of assuming ad hoc pollution diffusion schemes across space, we consider a realistic spatiotemporal law of motion for air and water pollution (diffusion and advection). Second, we tackle spatiotemporal non-cooperative (and cooperative) differential games. Precisely, we consider a circle partitioned into several states where a local authority decides autonomously about its investment, production and depollution strategies over time knowing that investment/production generates pollution, and pollution is transboundary. The time horizon is infinite. Third, we allow for a rich set of geographic heterogeneities across states while the literature assumes identical states. We solve analytically the induced non-cooperative differential game under decentralization and fully characterize the resulting long-term spatial distributions. We further provide with full exploration of the free riding problem, reflected in the so-called border effects. In particular, net pollution flows diffuse at an increasing rate as we approach the borders, with strong asymmetries under advection, and structural breaks show up at the borders. We also build a formal case in which a larger number of states goes with the exacerbation of pollution externalities. Finally, we explore how geographic discrepancies affect the shape of the border effects.

Mots clés: spatial externalities, environmental federalism, transboundary pollution, differential games in continuous time and space, infinite dimensional optimal control problems
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2020-17
Education, neopatrimonialism, and revolutions
Raouf Boucekkine
Rodolphe Desbordes
Paolo Melindi-Ghidi

The occurrence of some revolutionary episodes seems initially puzzling. For example, before the 'Arab Spring', macroeconomic conditions were improving, the political leaders had been in power for a long time, and the autocrats had shown an apparent interest in the welfare of their population by investing in human capital. We argue that such a paradox can be solved by considering that high education levels are incompatible with the features characterising strong neopatrimonial states. We develop this intuition in a simple theoretical model and we test our prediction in a sequential empirical study of regime changes and regime breakdowns in a large panel of countries. We indeed find that a regime change is more likely in countries combining high neopatrimonialism and high education levels. Moreover, when a regime change happens under these circumstances, a revolution is the most likely type of regime breakdown. These results help to understand the 'Arab Spring' but are not specific to the Arab world.

Mots clés: education, neopatrimonialism, regime breakdown, regime change, revolution
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2020-16
Coping with shocks: the impact of Self-Help Groups on migration and food security
Timothée Demont

This paper asks whether local savings and credit associations help poor rural households hit by climatic shocks. Combining data from an original field experiment with meteorological data, I investigate how Self-Help Groups (SHGs) allow households to cope with rainfall shocks in villages of East India over a sevenyear period. I show that SHGs withstand large rainfall shocks remarkably, and that credit flows are very stable in treated villages. As a result, treated households experience a higher food security during the lean season following a drought and increase seasonal migration to mitigate future income shocks. These results imply that small-scale financial institutions like SHGs help to finance temporary risk management strategies and to cope with important covariate income shocks such as droughts.

Mots clés: microfinance, weather shocks, risk management, seasonal migration, food security
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2020-15
Costly agreement-based transfers and targeting on networks with synergies
Mohamed Belhaj
Frédéric Deroïan
Shahir Safi

We consider agents organized in an undirected network of local complementarities. A principal with a limited budget offers costly bilateral contracts in order to increase the sum of agents' effort. We study excess-effort linear payment schemes, i.e. contracts rewarding effort in excess to the effort made in absence of principal. The analysis provides the following main insights. First, for all contracting costs, the optimal unit returns offered to every targeted agent are positive and generically heterogeneous. This heterogeneity is due to the presence of outsiders, who create asymmetric interaction between contracting agents. Second, when contracting costs are low, it is optimal to contract with everyone and optimal unit returns are identical for all agents. Third, when contracting costs are sufficiently high, it becomes optimal to target a subset of agents, and optimal targeting can lead to NP-hard problems. In particular, when the intensity of complementarities is sufficiently low, a correspondence is established between optimal targeting and the densest k subgraph problem. Overall, the optimal targeting problem involves a trade-off between centrality and budget spending-central agents are influential, but are also more budget-consuming. These considerations can lead the principal to not target central agents.

Mots clés: networked synergies, aggregate effort, optimal group targeting, linear contract
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2020-14
Feeling good or feeling better?
Alberto Prati
Claudia Senik

Can people remember correctly their past well-being? We study three national surveys of the British, German and French population, where more than 50,000 European citizens were asked questions about their current and past life satisfaction. We uncover systematic biases in recalled subjective well-being: on average, people tend to overstate the improvement in their well-being over time and to understate their past happiness. But this aggregate figure hides a deep asymmetry: while happy people recall the evolution of their life to be better than it was, unhappy ones tend to exaggerate its worsening. It thus seems that feeling happy today implies feeling better than yesterday. These results offer an explanation of why happy people are more optimistic, perceive risks to be lower and are more open to new experiences.

Mots clés: life satisfaction, remembered utility, memory biases, intra-personal comparisons
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2020-13
Does the Yield Curve Signal Recessions? New Evidence from an International Panel Data Analysis
Jean-Baptiste Hasse
Quentin Lajaunie

In this paper, we reexamine the predictive power of the yield spread across countries and over time. Using a dynamic panel/dichotomous model framework and a unique dataset covering 13 OECD countries over a period of 45 years, we empirically show that the yield spread signals recessions. This result is robust to different econometric specifications, controlling for recession risk factors and time sampling. Using a new cluster analysis methodology, we present empirical evidence of a partial homogeneity of the predictive power of the yield spread. Our results provide a valuable framework for monitoring economic cycles.

Mots clés: yield spread; recession; panel binary model; cluster analysis
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2020-12
Growth and instability in a small open economy with debt
Leonor Modesto
Carine Nourry
Thomas Seegmuller
Alain Venditti

The relationship between public debt, growth and volatility is investigated in a Barro-type (1990) endogenous growth model, with three main features: we consider a small open economy, international borrowing is constrained and households have taste for domestic public debt. Therefore, capital, public debt and the international asset are not perfect substitutes and the economy is characterized by an investment multiplier. Whatever the level of the debt-output ratio, the existing BGP features expectation-driven fluctuations. If the debt-output ratio is low enough, there is also a second BGP with a lower growth rate. Hence, lower debt does not stabilize the economy with credit market imperfections. However, a high enough taste for domestic public debt may rule out the BGP with lower growth. This means that if the share of public debt hold by domestic households is high enough, global indeterminacy does not occur.

Mots clés: small open economy, public debt, credit constraint, indeterminacy
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2020-11
Sub-National Allocation of COVID-19 Tests: An Efficiency Criterion with an Application to Italian Regions
Christelle Baunez
Mickael Degoulet
Stéphane Luchini
Patrick A. Pintus
Miriam Teschl

Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.

Mots clés: COVID-19; epidemic dynamics; acceleration of harm; deceleration of harm; real-time analysis; sub-national allocation of tests; efficiency criterion; Italy
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2020-10
Are the liquidity and collateral roles of asset bubbles different?
Lise Clain-Chamosset-Yvrard
Xavier Raurich
Thomas Seegmuller

Several recent papers introduce different mechanisms to explain why asset bubbles are observed in periods of larger growth. These papers share common assumptions, heterogeneity among traders and credit market imperfection , but differ in the role of the bubble, used to provide liquidities or as collateral in a borrowing constraint. In this paper, we introduce heterogeneous traders by considering an overlapping generations model with households living three periods. Young households cannot invest in capital, while adults have access to investment and face a borrowing constraint. Introducing bubbles in a quite general way, encompassing the different roles they have in the existing literature, we show that the bubble may enhance growth when the borrowing constraint is binding. More significantly, our results do not depend on the-liquidity or collateral-role attributed to the bubble. We finally extend our analysis to a stochas-tic bubble, which may burst with a positive probability. Because credit and bubble are no more perfectly substitutable assets, the liquidity and collateral roles of the bubble are not equivalent. Growth is larger when bubbles play the liquidity role, because the burst of a bubble used for liquidity is less damaging to agents who invest in capital.

Mots clés : bubble, liquidity, collateral, crowding-in effect, growth
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2020-09
Urgently Needed for Policy Guidance: An Operational Tool for Monitoring the COVID-19 Pandemic
Stéphane Luchini
Miriam Teschl
Patrick A. Pintus
Mickael Degoulet
Christelle Baunez
Jean-Paul Moatti

The radical uncertainty around the current COVID19 pandemics requires that governments around the world should be able to track in real time not only how the virus spreads but, most importantly, what policies are effective in keeping the spread of the disease under check. To improve the quality of health decision-making, we argue that it is necessary to monitor and compare acceleration/deceleration of confirmed cases over health policy responses, across countries. To do so, we provide a simple mathematical tool to estimate the convexity/concavity of trends in epidemiological surveillance data. Had it been applied at the onset of the crisis, it would have offered more opportunities to measure the impact of the policies undertaken in different Asian countries, and to allow European and North-American governments to draw quicker lessons from these Asian experiences when making policy decisions. Our tool can be especially useful as the epidemic is currently extending to lower-income African and South American countries, some of which have weaker health systems.

Mots clés: acceleration; convexity; covid-19; data dashboard; detection of infectious diseases; public health policy; sensitivity
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2020-08
Trends in intergenerational homeownership mobility in France between 1960-2015
Barbara Castillo Rico

We study intergenerational wealth mobility and its evolution in France over the period 1960-2015. More precisely, we identify the persistence of homeownership between parents and children as indicator of wealth mobility in France. We also provide evidence about different sources of heterogeneity in intergenerational homeownership associations in terms of education and geographic areas. Finally, we study the main transmission mechanism: direct financial transfers. We use all available French wealth surveys since 1986 and perform a data panelization using retrospective information. We document multiple results. First, intergenerational correlation in homeownership status has dramatically increased, particularly since the 1990s. Second, this rise is concentrated among people aged between 20 and 39 years old. Third, we observe higher wealth persistence at the top. Four, we find a strong significant effect of direct wealth transfers on the probability of becoming homeowner, which lasts 5 years. Moreover, parental support is substantially more important for households with no diploma, suggesting a crucial role of human capital on wealth formation. Finally, this phenomenon is intensified in areas with high urban concentration; highlighting the potential role of house prices as determinant of wealth social determinism.

Mots clés: intergenerational mobility, homeownership, housing, wealth transmission
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2020-07
Long-term growth impact of climate change and policies: the Advanced Climate Change Long-term (ACCL) scenario building model
Claire Alestra
Gilbert Cette
Valérie Chouard
Rémy Lecat

This paper provides a tool to build climate change scenarios to forecast Gross Domestic Product (GDP), modelling both GDP damage due to climate change and the GDP impact of mitigating measures. It adopts a supply-side, long-term view, with 2060 and 2100 horizons. It is a global projection tool (30 countries / regions), with assumptions and results both at the world and the country / regional level. Five different types of energy inputs are taken into account according to their CO2 emission factors. Full calibration is possible at each stage, with estimated or literature-based default parameters. In particular, Total Factor Productivity (TFP), which is a major source of uncertainty on future growth and hence on CO2 emissions, is endogenously determined, with a rich modeling encompassing energy prices, investment prices, education, structural reforms and decreasing return to the employment rate. We present four scenarios: Business As Usual (BAU), with stable energy prices relative to GDP price; Decrease of Renewable Energy relative Price (DREP), with the relative price of non CO2 emitting electricity decreasing by 2% a year; Low Carbon Tax (LCT) scenario with CO2 emitting energy relative prices increasing by 1% per year; High Carbon Tax (HCT) scenario with CO2 emitting energy relative prices increasing by 3% per year. At the 2100 horizon, global GDP incurs a loss of 12% in the BAU, 10% in the DREP, 8% in the Low Carbon Tax scenario and 7% in the High Carbon Tax scenario. This scenario exercise illustrates both the "tragedy of the horizon", as gains from avoided climate change damage net of damage from mitigating policies are negative in the medium-term and positive in the long-term, and the "tragedy of the commons", as climate change damage is widely dispersed and particularly severe in developing economies, while mitigating policies should be implemented in all countries, especially in advanced countries modestly affected by climate change but with large CO2 emission contributions.

Mots clés: climate, global warming, energy prices, government policy, growth, productivity, long-term projections
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2020-06
Children's socio-emotional skills: Is there a quantity-quality trade-off?
Simon Briole
Hélène Le Forner
Anthony Lepinteur

Although it is widely acknowledged that non-cognitive skills matter for adult outcomes, little is known about the role played by family environment in the formation of these skills. We use a longitudinal survey of children born in the UK in 2000-2001, the Millennium Cohort Study by the Centre for Longitudinal Studies, to estimate the effect of family size on socio-emotional skills, measured by the Strengths and Difficulties Questionnaire. To account for the endogeneity of fertility decisions, we use a well-known instrumental approach that exploits parents' preference for children's gender diversity. We show that the birth of a third child negatively affects the socio-emotional skills of the first two children in a persistent manner. However, we show that this negative effect is entirely driven by girls. We provide evidence that this gender effect is partly driven by an unequal response of parents' time investment in favour of boys and, to a lesser extent, by an unequal demand for household chores.

Mots clés: non-cognitive skills; family size; birth order; child development
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2020-05
Sweet child of mine: Parental income, child health and inequality
Nicolas Berman
Lorenzo Rotunno
Roberta Ziparo

How to allocate limited resources among children is a crucial household decision, especially in developing countries where it might have strong implications for children and family survival. We study how variations in parental income in the early life of their children affect subsequent child health and parental investments across siblings, using micro data from multiple waves of the Demographic and Health Survey (DHS) spanning 54 developing countries. Variations in the world prices of locally produced crops are used as measures of local income. We find that children born in periods of higher income durably enjoy better health and receive better human capital (health and education) investments than their siblings. Children whose older siblings were born during favourable income periods receive less investment and exhibit worse health in absolute terms. We interpret these within-household reallocations in light of economic and evolutionary theories that highlight the importance of efficiency considerations in competitive environments. Finally, we study the implications of these for aggregate child health inequality, which is found to be higher in regions exposed to more volatile crop prices.

Mots clés: health, income, parental investments, intra-household allocations
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2020-04
Religion, Politics, and Judicial Independence: Theory and Evidence
Sultan Mehmood
Avner Seror

Most enlightenment philosophers argued that the separation between Church and State would prevent capture of resources by one state religion. We formalize and test a theory that addresses a different danger. We demonstrate that a reduction in the separation between Church and State can be corrosive to political institutions, especially the Judiciary. We show that religious leaders use their high legitimacy to gain political office, and become particularly abusive politicians, misusing their political authority to undermine the independence of the Judiciary. We provide a theoretical framework and estimate the structural equations of our theory using data from Pakistan. Our empirical strategy exploits the plausibly exogenous timing of a military coup to provide causal evidence for the key predictions of our theory.

Mots clés: religion, judicial independence, elections, economic development
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2020-03
Optimal location of economic activity and population density: The role of the social welfare function
Raouf Boucekkine
Giorgio Fabbri
Salvatore Federico
Fausto Gozzi

In this paper, we consider a spatiotemporal growth model where a social planner chooses the optimal location of economic activity across space by maximization of a spatiotemporal utilitarian social welfare function. Space and time are continuous, and capital law of motion is a parabolic partial differential diffusion equation. The production function is AK. We generalize previous work by considering a continuum of social welfare functions ranging from Benthamite to Millian functions. Using a dynamic programming method in infinite dimension, we can identify a closed-form solution to the induced HJB equation in infinite dimension and recover the optimal control for the original spatiotemporal optimal control problem. Optimal stationary spatial distributions are also obtained analytically. We prove that the Benthamite case is the unique case for which the optimal stationary detrended consumption spatial distribution is uniform. Interestingly enough, we also find that as the social welfare function gets closer to the Millian case, the optimal spatiotemporal dynamics amplify the typical neoclassical dilution population size effect, even in the long-run.

Mots clés: spatiotemporal growth models, Benthamite vs Millian social welfare functions, imperfect altruism, diffusion, dynamic programming in infinite dimension
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2020-02
A theory of heterogeneous city growth
Christian Ghiglino
Kazuo Nishimura
Alain Venditti

We consider an economy with three cities producing different outputs. Two cities produce intermediate goods, a type 1 producing an intermediate "agricultural" good with capital and labor only, and a type 2 producing an intermediate "industrial" good with capital, labor and human capital, and the last type 3 city produces the final good which is obtained from the two intermediate goods and labor. The asymmetric introduction of human capital allows us to prove that the three cities experience at the equilibrium heterogeneous endogenous growth rates which are proportional to the growth rate of human capital. We show that the "industrial" type 2 city is characterized by the larger growth rate while the "agricultural" type 1 city experiences the lower growth rate, and thus the type 3 city is characterized by a growth rate which is a convex combination of the two formers. This implies that the relative size in terms of output of the "agricultural" city decreases over time. This property allows to recover the empirical fact that most nonagricultural production occurs in growing metropolitan areas. But, simultaneously, as we prove that total labor employed in each city is proportional to the total population, the relative population size distribution of cities is constant over time as shown in empirical studies.

Mots clés: urban dynamics, human capital, endogenous growth, heterogeneous growth rates, city inequalities
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2020-01
Lie of the Weak: Inconsistent Corporate Social Responsibility Activities of Chinese Zombie Firms
Shaozhen Han
Guoming Li
Michel Lubrano
Zhou Xun

This study investigates the differences between zombie firms and non-zombie firms in corporate social responsibility activities such as reporting, disclosure and fulfillment. Using Chinese listing company data collected from 2009 to 2016, we apply a three stage model with a double Heckman correction to deal with potential self-selection/endogeneity bias and to measure the differences consistently. We found that zombie firms are less willing to release standalone corporate social responsibility reports than non-zombie firms. Among companies that release standalone corporate social responsibility reports, the corporate social responsibility disclosure of zombie firms is at least not worse than non-zombie firms, but the corporate social responsibility fulfillment is significantly lower. We conclude from this gap between disclosure and fulfillment to the hypocritical behavior of zombie firms, due to the absence of control in corporate social responsibility. We suggest that government should enhance supervision over zombie firms’ corporate social responsibility activities and subsidies towards them in order to lower their economic damage. Supplementary analyses provide some clues concerning the heterogeneity of inconsistence in term of external support characteristics, ownership and censorship which require further studies.

Mots clés: corporate social responsibility; zombie firms; reports; disclosure; fulfillment; hypocrisy
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