THEMA

“Gender, Inheritance and Fertility” Workshop

ygustave — 2025-12-16T09:53:00Z

“Gender, Inheritance and Fertility” Workshop

This workshop brings together economists to discuss the intersections between gender, inheritance, and fertility. Through studies covering contexts as diverse as contemporary Nigeria and pre-industrial France, the presentations examine how inheritance norms shape fertility, power dynamics within couples, and the position of women in society. The contributions explore, among other things, the effects of inheritance rights on fertility choices, intrafamily bargaining in polygamous households, and the role of inheritance norms in marriage formation in Europe and in women's emancipation. By drawing on rigorous empirical approaches and original data, this workshop sheds light on the ways in which rules of transmission durably influence demographic dynamics and gender inequalities.

Lien vers le programme du workshop : https://docs.google.com/document/d/1PbxlFFkbJ66dLVmZZf2fykcCKeuPcPv0/edit

Carlos SERRANO - HEC PARIS

2025-12-16T08:46:58Z

“Acquiring Patents in Secret : Disclosure Timing in Markets for Technology."
(George Chondrakis, Carlos Serrano, Rosemarie Ziedonis)

Abstract : Markets for technology provide a vibrant channel through which firms purchase ownership rights to patented inventions. Although such transactions enable firms to secure access to intangible assets originating beyond their borders, they also provide cues to competitors regarding the purchasing firm's technological investments. This study explores the timing of strategic disclosure of patent acquisitions and the conditions under which firms trade the benefits of competitor deterrence through early recordation for those of secrecy through delayed disclosure. Using evidence on the lag between the execution and recording dates for US patents purchased by publicly traded corporations, we predict and find earlier disclosure of patent acquisitions when the buyer works on related technologies and is better positioned to enforce the patents (i.e., is large and relatively litigious). As predicted by the model, we also find that the buyer delays disclosure when the seller is a large firm, suggesting that buyers take advantage of the seller's ability to deter competitors while keeping the transaction secret. Additional analyses reveal that (a) regulatory changes reducing the value of keeping acquisitions of patent applications secret lead to shorter recording lags, and (b) increases in the enforceability of business method and software patents further accelerate the voluntary recording of patent ownership changes. The study provides new evidence on the tradeoffs that innovating firms face when determining the timing of disclosure for patents they have purchased in technology markets.

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

Graziella BERTOCCHI - UNIVERSITA DI MODENA E REGGIO EMILIA

ygustave — 2025-12-08T09:51:43Z

"Family Planning and Ethnic Heritage : Evidence from Sub-Saharan Africa"
with Arcangelo Dimico and Chiara Falco

Abstract :
Using ethnographic, ecological, and folklore data for sub-Saharan Africa, we investigate the role played by postpartum sexual abstinence, an extensively documented practice that in preindustrial societies finds its biological justification as a means to safeguard child survival. We show that the duration of contemporary postpartum abstinence increases with that of ancestral postpartum sex taboos within a woman's ethnic group ; raises fertility ; lengthens birth intervals though not sufficiently to meet recommended guidelines ; is detrimental for children's health ; is associated with lower age at first birth and female disempowerment ; and is adopted
as a purification ritual, out of respect of ancestral traditions.

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

Sylvain CARRE - UNIVERSITE PARIS I PANTHEON SORBONNE

ygustave — 2025-12-01T08:41:03Z

"Efficiency in DeFi Lending : Interest Rate Mechanisms and Liquid Staking"
joint work with Franck Gabriel)

Abstract : Liquid staking, a notable recent innovation in decentralized finance (DeFi) allows to delegate and redeploy capital which was traditionally locked and has thus been promoted for its “capital efficiency” virtues. In the context of DeFi lending, we build a tractable general equilibrium model to analyze two strategic interactions between investors, which, we show, affect the performance of liquid vs traditional staking. We find that without a proper adjustment of the DeFi lending interest rate mechanism, liquid staking can worsen efficiency even when there are no delegation costs. When the interest rate is optimally set, a combination of mild delegation costs and limited investor competition can lead to the same conclusion.

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.

Alexandre DE CORNIERE - TOULOUSE SCHOOL OF ECONOMICS

ygustave — 2025-11-24T07:17:17Z

"Seller-Side Tying of Platform Services, joint with Kinshuk Jerath and Greg Taylor"

Abstract :
This paper analyzes the practice of seller-side tying in digital platforms, where access to a core intermediation service is conditioned on the seller using ancillary services such as fulfillment or payment processing. We develop a model in which a monopoly platform intermediates transactions between consumers and competing sellers, and can choose whether to force the sellers to tie a costly ancillary service to the core offering. Consumers value the ancillary service heterogeneously, and seller adoption decisions generate vertical differentiation that affects market prices and consumer platform participation. We show that tying resolves under-adoption of the ancillary service, increases competition between sellers, and raises consumer surplus. In contrast, a ban on tying or a structural separation of the platform reduces service adoption and harms consumers. These results differ from consumer-side tying where, in our setting, bundling the core and ancillary services is neither profitable for the platform nor beneficial to consumers. The efficiency rationale for seller-side tying is robust under multiple variations of our main model.

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.

Gabrielle FACK - DAUPHINE UNIVERSITY- PSL

ygustave — 2025-11-17T07:54:30Z

« The Effects of Affirmative Action on Targeted and Non-Targeted Students : Evidence from Low-Income Priorities in Paris High Schools »
Gabrielle Fack (Université Paris Dauphine-PSL), Julien Grenet (Paris School of Economics), YingHua He (Rice University)