Documents de travail
wp_2025_nr_10.pdf (232.66 Ko) This article establishes a direct proof of the equivalence between two incomplete rankings of distributions of an ordinal attribute. The first ranking is the possibility of going from one distribution to another by a finite sequence of Hammond transfers. The second ranking is the intersection of two dominance criteria introduced by Gravel et al.(Economic Theory, 71 (2021), 33-80). The proof constructs an algorithm that provides a series of Hammond transfers, between any two distributions related by the intersection of the two dominances.
wp_2025_nr_09.pdf (794.53 Ko) Agricultural policies in poor rural developing countries have the potential to improve both household nutrition and agricultural income. But can these policy consequences be reconciled? This is not obvious because many policies are deficient. Moreover, in villages, mismatches have been observed between nutrition and profit indicators. However, incomes raised by such policies may generate nutrition improvement. In Niger, a major program directed to agro-pastoralists is the 3N Initiative. Do these policies enhance households’ agricultural profit and dietary intakes? And if so, is it because of an income effect, or through alternative channels? Using an agropastoral survey conducted in 2016 Niger, we find that livestock extension services that reduce calorie intake while improving diet diversity operate mostly through an increased household’s pastoral profit. In contrast, veterinary services and low-cost livestock feed programs improve diet diversity, but do not affect profit and calories. Because livestock extension services foster households specializing in cattle and sheep rearing and sometimes switching to transhumance, they restrict their access to energy-dense cereals. This generate a perverse consequence on caloric intakes, despite rising animal calories. Therefore, nutritional policy-makers should better account for agro-pastoralist access to cereal markets and monitor whether policies generate differential incentives, especially through profit, for specific specialization or lifestyle.
wp_2025_nr_08.pdf (894.89 Ko) The transition towards a sustainable food system requires comprehensive changes in food production and consumption, shaped by the interplay of public policy, market forces, and cultural norms. We develop a model to analyse the role of sustainable food culture in shaping consumption choices, particularly in terms of purchasing from short food supply chains. The model accounts not only for the heterogeneity of preferences and their evolution but also for the heterogeneity of incomes. This allows for a discussion of the effectiveness of policies fostering sustainable food consumption choices, considering their varying impacts across income levels. The results suggest that if policy makers seek to promote a sustainable food system, public policies must be carefully designed, as their effects can be uncertain and may impact low-income households.
wp_2025_nr_07.pdf (530.48 Ko) This paper develops a dynamic model of addiction on networks, where individuals’ consumption is shaped by peer influence. We analyze the longrun effects of social interactions by characterizing steady-state consumption as a function of both network position and forward-looking behavior. We also examine the welfare implications of network structure and evaluate the effectiveness of various public policies aimed at reducing the demand for addictive goods. In particular, we study a key-player policy—modeled as a targeted rehabilitation program—that leverages the network’s interpersonal influences to maximize impact.
wp_2025_nr_06_.pdf (560.04 Ko) Experts argue that the adoption of healthy sanitation practices, such as hand washing and latrine use, requires focusing on the entire community rather than individual behaviors. According to this view, one limiting factor in ending open defecation lies in the capacity of the community to collectively act toward this goal. Each member of a community bears the private cost of contributing by washing hands and using latrines, but the benefits through better health outcomes depend on whether other community members also opt out of open defecation. We rely on a community-based intervention carried out in Mali as an illustrative example (Community-Led Total Sanitation or CLTS). Using a series of experiments conducted in 121 villages and designed to measure the willingness of community members to contribute to a local public good, we investigate the process of participation in a collective action problem setting. Our focus is on two types of activities: (1) gathering of community members to encourage public discussion of the collective action problem, and (2) facilitation by a community champion of the adoption of individual actions to attain the socially preferred outcome. In games, communication helps raise public good provision, and both open discussion and facilitated ones have the same impact. When a community member facilitates a discussion after an open discussion session, public good contributions increase, but there are no gains from opening up the discussion after a facilitated session. Community members who choose to contribute in the no-communication treatment are not better facilitators than those who choose not to contribute.
wp_2025_-_nr_05.pdf (1.17 Mo) Using data from a selection of Latin American countries affected by El Ni˜no-Southern Oscillation climate phenomena, we observe that extreme weather events can be highly disruptive for an economy, particularly in the agricultural sector, while also giving rise to inflationary pressures. Motivated by these findings, this paper examines the optimal stabilization policies for a climate-vulnerable economy with two segmented sectors: agriculture (producing food) and manufacturing. In response to climate disasters affecting agriculture, it is found to be optimal to increase fiscal transfers to farmers while maintaining core inflation at its target level. Deviating from the optimal policy mix results in smaller welfare losses as long as core inflation remains stabilized.
wp_2025_-_nr_04.pdf (2.14 Mo) Based on the calibration of a simple model, we decompose the decline in the labor share into four structural components: task displacement, labor rents, capital rents, and labor-capital substitution effect. Our estimation suggests that task displacement and the switch of distributed rents from labor to capital are the main drivers of the labor share decline over the past three decades. On the other hand, the neoclassical substitution effect seems not to have a long term impact on the labor share.
wp_2025_nr_03.pdf (1.64 Mo) This paper analyzes how collateral quality shocks affect banks’ liquidity management and the risk-free rate. We develop a model where banks manage liquidity through near-cash assets and marketable securities subject to idiosyncratic and/or aggregate shocks. Collateral quality deterioration leads to non-monotonic changes in liquidity holdings: moderate declines reduce cash holdings via lower market returns, while severe declines cause precautionary hoarding and market freezes. Reduced collateral quality depresses the risk-free rate. Policy interventions, including liquidity regulation and negative interest rate policies can mitigate these effects. Our findings highlight the risks of collateral quality shocks and the importance of policy complementarities in addressing liquidity issues.
wp_2025_-_nr_02.pdf (775.99 Ko) In this paper, we examine the possibility for a regulator to reduce policy costs by substituting a voluntary policy based on a legislative threat to an active harvest control. Specifically, we focus on fisheries where the regulator aims to maintain an optimal level of conservation through a voluntary agreement. To achieve this, we identify a mandatory regulation that can serve as a threat to ensure voluntary compliance and avoid regulation costs. However, threats differ from effective policies. To be enforceable, they must be validated through a legislative process, the outcome of which is uncertain and subject to objections. Consequently, we introduce of a random delay in its application and address issues of social acceptability. This threat rests upon two pillars: a moratorium with financial compensation followed by an Individual Transferable Quota (ITQ) mechanism, and a suitably chosen tax on harvesting capacity to deter deviations. We use data from the scallop fishery in the Bay of Saint-Brieuc (France) to illustrate this voluntary mechanism.
wp_2025_-_nr_01pdf.pdf (790.58 Ko) We test the existence of cheap talk between husbands and wives working together in a family business. Our setting is the farm household. We designed an experiment, contextualized as an input allocation game, in which the husband chooses the amount of resources to invest on his own plot and on his wife's land. The return from the land managed by the wife is higher. We experimentally vary whether the returns from the wife's plot are communicated to the husband (i) by the experimenter, (ii) by the wife herself, and (iii) by the wife herself but with the possibility for the husband to verify the accuracy of the information from the experimenter after he makes his allocation decision. Male producers allocate too few inputs to their wife's plot across all experimental conditions. We rationalize these ndings in a setting with limited enforcement of marital agreements and derive additional predictions. First, allocative ineciencies in production are worse when women hold private information compared to the full information treatment. This e ect is stronger for households for which resource-sharing under full information is lower. Second, communication between spouses can only compensate for damages from private information when the information is veri able ex post.
wp_2019_-_nr_37_0.pdf (710.3 Ko) 
