Portail HAL Paris School of Economics (PSE)
Not a member yet
5677 research outputs found
Sort by
Identifying and interpreting the factors in factor models via sparsity: Different approaches
No full textInternational audienceWith the usual estimation methods of factor models, the estimated factors are notoriously difficult to interpret, unless their interpretation is imposed via restrictions. This paper considers different methods to identify the factor structure and interpret the factors without imposing their interpretation: sparse PCA and factor rotations. We establish a new consistency result for the factors estimated by sparse PCA. Monte Carlo simulations show that our exploratory methods accurately estimate the factor structure, even in small samples. We also apply them on two standard large datasets about international business cycles and the US economy: for each empirical application, they identify the same factor structure, offering a clear economic interpretation of the estimated factors. These exploratory methods can be useful to justify or complement approaches in which the factor structure is imposed a priori
David Card, Prix Nobel 2021: la révolution design-based
No full textInternational audienceAu tournant des années 1990, David Card est l’un des principaux initiateurs d’une évolution majeure de la recherche en sciences économiques. A partir de ce moment, la qualité d’une recherche empirique ne se juge plus seulement à ses liens avec un modèle théorique formel, mais aussi et avant tout à la pertinence des hypothèses sous lesquelles sont identifiées les relations de cause à effet entre grandeurs économiques. S’appuyant sur une palette de méthodes quasi-expérimentales, David Card contribue de manière décisive à nombre de débats majeurs, dont ceux sur le salaire minimum, l’immigration, la ségrégation raciale ou l’éducation. La recherche empirique en économie gagne en autonomie, en prestige et en audience, notamment auprès des autres sciences sociales. A partir d’une analyse inédite des publications de certaines revues emblématiques, nous retraçons la façon dont les approches quasi expérimentales promues par David Card ont fini par se diffuser en Europe et en France
A Dilemma between Liquidity Regulation and Monetary Policy: some History and Theory
No full textInternational audienceHistory suggests a conflict between current Basel III liquidity ratios and monetary policy, which we call the liquidity regulation dilemma. Although forgotten, liquidity ratios, named “securities-reserve requirements,” were widely used historically, but for monetary policy (not regulatory) reasons, as central bankers recognized the contractionary effects of these ratios. We build a model rationalizing historical policies: a tighter ratio reduces the quantity of assets that banks can pledge as collateral, thus increasing interest rates. Tighter liquidity regulation paradoxically increases the need for central bank's interventions. Liquidity ratios were also used to keep yields on government bonds low when monetary policy tightened
Vaccination under pessimistic expectations in clinical trials and immunization campaigns
No full textInternational audienceWe provide one of the first formalizations of a vaccination campaign in a decisiontheoretic framework. We analyse a model where an ambiguity-averse individual must decide how much effort to invest into prevention in the context of a rampant disease. We study how ambiguity aversion affects the effort and the estimation of the vaccine efficacy in clinical trials and immunization campaigns. We find that the behaviours of individuals participating in a clinical trial differ from individuals not participating. Individuals who are more optimistic toward vaccination participate more in trials. Their behaviours and efforts are also affected. As a result, because vaccine efficacy depends on unobserved behaviours and efforts, the biological effect of the vaccine becomes difficult to evaluate. During the scale-up phase of a vaccination campaign, provided that vaccine efficacy is established, we show that vaccine hesitancy may still be rational
Les aliments produits à l'aide de nouvelles techniques d'ingénierie végétale peuvent-ils réussir sur le marché ? Une étude de cas avec des pommes
No full textInternational audienceWe present a model for research and development (R&D) investment in food innovations based on new plant engineering techniques (NPETs) and traditional hybridization methods. The framework combines uncertain and costly food innovation with consumers' willingness to pay (WTP) for the new food. The framework is applied with elicited WTP of French and US consumers for new improved apples. NPETs may be socially beneficial under full information and when the probability of success under NPETs is relatively high. Otherwise, the traditional hybridization is socially optimal. A probable collapse of conventional apples raises the social desirability of new apples generated by NPETs and traditional hybridization.Nous présentons un modèle d'investissement en recherche et développement (R&D) dans le domaine alimentaire, en prenant en considération les nouvelles techniques d'ingénierie végétale (NTIV) et les méthodes d'hybridation traditionnelles. Le modèle intègre une innovation alimentaire incertaine et coûteuse, ainsi que les consentements à payer des consommateurs (CAP) pour le nouvel aliment. Ce cadre conceptuel est appliqué au cas de nouvelles pommes se conservant plus longtemps et brunissant moins vite, en prenant en compte les CAP des consommateurs français et américains pour ces nouvelles pommes. Il est montré que les NTIV peuvent être socialement bénéfiques dans un contexte d’information complète, et lorsque la probabilité de succès avec ces NTIV est relativement élevée. Sinon, l'hybridation traditionnelle est socialement optimale. Une menace importante sur la production des pommes conventionnelles augmente la désirabilité sociale de nouvelles pommes générées par les NTIV ou l'hybridation traditionnelle
Global Tax Evasion Report 2024
No full textOver the last 10 years, governments have launched major initiatives to reduce international tax evasion. Yet despite the importance of these developments, little is known about the effects of these new policies. Is global tax evasion falling or rising? Are new issues emerging, and if so, what are they? This report addresses these questions thanks to an unprecedented international research collaboration building on the work of more than 100 researchers globally
Alcohol Price Regulation in France: Choosing a Reform Scenario to Achieve Public Health and Tax Fairness Objectives
No full textNational audiencePublic health authorities advocate the introduction of alcohol pricing policies in the form of tax reform and/or a minimum unit price based on the pure alcohol content of products. We use Kantar WorldPanel household purchase data to describe the distortions in the current tax system, favouring wine and penalising low-income households. We assess the potential impact of reform scenarios that replace current taxes with a single excise tax (flat or progressive) on pure alcohol content and/or the introduction of a minimum price per gram of pure alcohol. Introducing a minimum price while leaving taxation unchanged would have the advantage of raising alcohol prices, especially for low-end wines, which are prized by abusive consumers. The impact would a priori be limited in terms of tax regressivity and for higher quality segments, which is important for the wine sector
Targeting taxes on local externalities
No full textInternational audienceWe consider optimal anonymous consumption taxes in situations where the magnitude of an externality varies with individuals who cause it. For instance, urban fuel consumers generate greater pollution damages compared to rural consumers, but both groups are subjected to the same fuel tax. We provide a condition for the validity of the targeting principle, where external concerns are only addressed through the tax imposed on the commodity responsible for the externality. When this condition holds, one can separate the equity/efficiency and environmental components of this tax. An illustration suggests that Pigovian considerations explain most of the fuel tax in France
Overuse of caesareans: Potential healthcare and financial benefits of prenatal education
No full textInternational audienc
African firms in global value chains: What can we learn from firm‐level data in Cameroon and Côte d'Ivoire?
No full textInternational audienceThe paper offers a detailed review of African firms' participation to international value chains and provides new quantitative insights on two countries, Cameroon and Ivory Coast, based on a unique dataset, which was obtained by merging firm census and detailed customs transactions over time. “GVC firms” are defined as firms that both export and import, with positive production and labour. The paper characterises GVC firms in the two countries. GVC firms represent about 15% of manufacturing firms; they are more frequent than pure exporters, a sign of the challenges faced by firms in those countries if they want to sell abroad. In line with the literature on firm heterogeneity and trade, firms engaged in GVCs are larger, more productive and live longer than one‐way‐traders or domestic firms. African markets are the main destination of manufacturing GVCs in Ivory Coast, while Cameroon GVC firms rely on OECD (including for agricultural exports). There is limited cross‐penetration between African‐oriented and OECD‐oriented GVC firms over time. The probability of moving into a GVC is higher for exporters than for importers, showing that exporting is a stepping stone for African firms to join a GVC