THEMA

Omar AL HUMSI

lcollin — 2025-12-10T11:14:32Z

"Redistributive Labor Income Taxation with Directed Technical Change in a Unionized Economy"
Abstracts : What are the implications of endogenous directed technical change for the design of redistributive income taxes in a unionized economy ? I study this within a general equilibrium framework featuring two types of labor that supply labor along the extensive margin. Wages are determined through union–firm bargaining, while the direction of technology is chosen endogenously by (...)

- Séminaire Economie Théorique et Appliquée

Eddy ZANOUTENE

lcollin — 2025-12-04T07:17:22Z

"Optimal Taxation of Undistributed Profits (with Etienne Lehmann)"
Abstracts : We study the optimal combination of corporate and dividend taxes when retained earnings can be used to avoid taxation. We show that eliminating dividend taxes while raising the corporate income tax can increase total revenue without affecting investment. Our simulations indicate revenue gains of 0.1–0.5\% of GDP. In an infinite-horizon model, the optimal policy sets dividend taxes to zero in every period. This (...)

- Séminaire Economie Théorique et Appliquée

Margaux Suteau

lcollin — 2025-11-27T07:16:09Z

"Empowering Parents in the Digital Age"

Abstracts : While economic research documents substantial negative effects of social media on youth outcomes, the role of parents in mediating these effects remains largely unexplored. We propose digital parenting as a new form of human capital investment and test whether interventions can shift parents' beliefs and practices, as well as children's outcomes. Drawing on a UK household longitudinal survey, Understanding Society, we first document that intensive social media use is associated with greater behavioural problems among children, and that parenting styles predict children's digital exposure. We then conduct our own longitudinal survey on 1,800 UK parents, and implement two randomized interventions : (i) an information treatment providing evidence on the risks of social media, and (ii) a four-week video training on digital parenting strategies. The information treatment increased support for school no-phone policies by 47% relative to the control group mean and actual participation in follow-up training by 37%, though it also raised parental anxiety by 20%. The video training generates suggestive evidence of improvements in parenting practices, particularly communication strategies. Effects on children's outcomes are modest but suggest reductions in screen time. Treatment effects vary substantially by parenting style : permissive parents respond most strongly to both interventions. These findings suggest that while providing information can effectively shift beliefs and, to some extent, practices, it involves welfare trade-offs.

Linus Thierry NANA NOUMI

lcollin — 2025-11-20T08:32:43Z

"Measuring Differences of Opinion : Axiomatic Foundation, Utility, and Truthtelling"

Abstracts : Understanding how individuals and groups differ in their opinions and preferences is central to analyzing disagreement, measuring polarization, designing institutions, and predicting collective outcomes. Yet comparing preferences requires more than observing how each person ranks alternatives—it requires a method for comparing preference orderings themselves. This paper develops a formal framework to infer how individuals might rank different preference orderings based solely on their observed preferences. We introduce a set of natural and behaviorally plausible axioms—Independence (I), Disagreement Aversion (DA), and Symmetry (S)—and show that they uniquely characterize a class of hyperpreference relations and their associated utility representations. We apply this framework to the study of aggregation mechanisms, deriving necessary and sufficient conditions on utility structures that induce truthful preference reporting in equilibrium and guarantee efficiency. Our results yield new insights into strategyproof mechanism design under deep preference heterogeneity and clarify when differences of opinion can be meaningfully and reliably measured.

Javier TERRERO

lcollin — 2025-11-13T07:32:19Z

"Who Gets Ahead ? Comparative Evidence on Intragenerational Mobility from Administrative Microdata"

Abstracts : We use administrative records from Austria, Belgium, Estonia and Spain to study income dynamics of working-age individuals over five years. Aggregate mobility indices often mask substantial variation in short-term income trajectories for individuals at different points of the distribution. By combining relative and absolute mobility metrics that can be aggregated at the percentile level, we provide granular comparative evidence of intragenerational mobility both across countries and across socio-demographic groups. Our results show that cross-country differences in mobility patterns are particularly pronounced at the bottom and top of the distribution, while outcomes in the middle are more alike. Large cross-country differences in relative income growth or rank advancement at the bottom often translate into only modest differences in absolute living standards, underscoring the importance of considering different mobility metrics when comparing mobility across countries. Overall, Estonia exhibits greater relative and absolute intragenerational mobility than the other three countries. Across demographic groups, individuals with lower educational attainment and immigrants experience weaker mobility outcomes across the entire distribution in all countries. Women experience worse mobility outcomes at the bottom of the distribution, although the gap narrows in the upper half in Belgium, Estonia and Spain. Age and rural–urban differences vary by initial income position and are not consistent across countries.

Markus POSCHKE

lcollin — 2025-10-28T14:27:59Z

"Skill Supply, Firm Size, and Economic Development"

Abstracts : This paper harmonizes individual-level data on labor supply for 54 countries to document how firm size and the skill intensity of employment by firm size vary across countries. First, it finds that the share of employment in large firms in high-income countries is more than three times larger than in low-income countries. Second, it shows that across countries, employees of large firms are more skilled than those of small firms. Third, it documents that lower skill endowments in low-income countries affect employment in firms of different sizes asymmetrically : the skill intensity of employment is much lower in small firms in low-income countries than in high-income countries, but only slightly lower in large firms. This evidence suggests that large firms rely particularly strongly on employing high-skill workers, so that the low skill endowment of low-income countries limits the size of firms in these countries.

Usama JAMAL

lcollin — 2025-10-16T05:59:20Z

"Tax Rules and Capital Reallocation : Real Effects of Anti-Tax Avoidance Policies"

Abstracts : Anti-tax avoidance policies aim to curb profit shifting by MNEs, yet their effects on capital costs and economic growth remain a critical question. This study examines the causal impacts of Earnings Stripping Rules (ESR)---an anti-avoidance measure adopted by over 45 jurisdictions between 2015 and 2023---that limit profit shifting through debt channels but increase the cost of debt-financed capital. Using a large panel dataset on global MNE operations and a staggered difference-in-difference design, I compare the real activities of MNEs affected by ESR with those of unaffected groups. I find that ESR effectively reduce profit shifting and tax avoidance but lower investments in affected subsidiaries. However, MNEs reallocate these investments to other subsidiaries, maintaining overall group-level investments. This reallocation takes place either abroad, to affiliates outside ESR jurisdictions, or within-country when all affiliates are within-ESR jurisdictions, allowing MNEs to maintain overall group-level investment. These findings suggest that coordinated and well-targeted anti-tax avoidance rules can reduce tax avoidance without stifling overall investment.

Mohammad LASHKARBOLOOKIE

lcollin — 2025-10-07T12:11:39Z

"Prosocial Disclosure and Contracts"

Abstracts : This paper studies prosocial disclosure (e.g., ESG reporting) and prosocial contracts (e.g., sustainability-linked loans) in a multitasking principal–agent framework with limited liability and private agent types. The agent exerts costly effort on two tasks : one yielding an unverifiable outcome and another generating an outcome that can be verifiably disclosed at a cost. The agent's private type captures their intrinsic utility over the outcomes, which affects both parties' gain from contracting on the verifiable information. The main result is the ambiguous effect of a mandatory disclosure regulation. While a disclosure mandate can enhance prosocial effort and welfare when the voluntary regime yields non-disclosure, it can reduce welfare when full disclosure emerges voluntarily. In cases where voluntary disclosure is partial, mandating disclosure can either improve or undermine contracting efficiency and welfare, depending on the specification of agent types and the principal's objective.

Maxime BERROU

lcollin — 2025-10-02T06:38:46Z

"Domestic tax reform and plants' production decisions : Evidence from India"

Abstract : I study how commodity taxation shapes manufacturing plants' sourcing and production decisions. Exploiting the introduction of the Goods and Services Tax (GST) in India in 2017, which removed input taxes for most sectors, I implement a difference-in-differences design using plant-level panel data from 2010 to 2022. I find that eligible plants faced a 43% reduction in their effective tax burden, increased both the quantity and variety of inputs sourced, and shifted production towards goods qualifying for input tax credits. The effects are strongest in regions with lower input tariffs and further away from major ports, highlighting complementarities between tax and trade policy. These results shed light on the way sectoral exemptions, meant to reduce the administrative burden of production plants, also impact the efficiency of domestic input markets.

Linus Thierry NANA NOUMI

lcollin — 2025-09-24T10:32:08Z

"Measuring Differences of Opinion : Axiomatic Foundation, Utility, and Truthtelling"

Abstract : Understanding how individuals and groups differ in their opinions and preferences is central to analyzing disagreement, measuring polarization, designing institutions, and predicting collective outcomes. Yet comparing preferences requires more than observing how each person ranks alternatives---it requires a method for comparing preference orderings themselves. This paper develops a formal framework to infer how individuals might rank different preference orderings based solely on their observed preferences. We introduce a set of natural and behaviorally plausible axioms---Independence (I), Disagreement Aversion (DA), and Symmetry (S)---and show that they uniquely characterize a class of hyperpreference relations and their associated utility representations. We apply this framework to the study of aggregation mechanisms, deriving necessary and sufficient conditions on utility structures that induce truthful preference reporting in equilibrium and guarantee efficiency. Our results yield new insights into strategyproof mechanism design under deep preference heterogeneity and clarify when differences of opinion can be meaningfully and reliably measured.