Publications
We identify two counteracting effects of credit access on productivity growth: on the one hand, better access to credit makes it easier for entrepreneurs to innovate; on the other hand, better credit access allows less efficient incumbent firms to remain longer on the market, thereby discouraging entry of new and potentially more efficient innovators. We first develop a simple model of firm dynamics and innovation‐based growth with credit constraints, where the above two counteracting effects generate an inverted‐U relationship between credit access and productivity growth. Then we test our theory on a comprehensive French manufacturing firm‐level dataset. We first show evidence of an inverted‐U relationship between credit constraints and productivity growth when we aggregate our data at the sectoral level. We then move to firm‐level analysis, and show that incumbent firms with easier access to credit experience higher productivity growth, but that they also experience lower exit rates, particularly the least productive firms among them. To support these findings, we exploit the 2012 Eurosystem's Additional Credit Claims programme as a quasi‐experiment that generated an exogenous extra supply of credits for a subset of incumbent firms.
The Great Recessions was essentially a “mancession” in countries like Spain, the UK, or the USA, i.e., it hist men harder than women for they were disproportionately represented in heavily affected sectors. We investigate how the mancession, and more generally women’s relative opportunities on the labor market, translates into within-household redistribution. Precisely, we estimate the spouses’ resource shares in a collective model of consumption, using Spanish data over 2006–2011. We exploit the gender-oriented evolution of the economic environment to test two original distribution factors: first the regional-time variation in spouses’ relative unemployment risks, and then the gender-differentiated shock in the construction sector (having a construction sector husband after the outburst of the crisis). Both approaches conclude that the resource share accruing to Spanish wives increased by around 7–9% on average, following the improvement of their relative labor market positions. Among childless couples, we document a 5–11% decline in individual consumption inequality following the crisis, which is essentially due to intrahousehold redistribution.
The stability of Nash equilibria has often been studied by examining the asymptotic behavior of the best-response dynamics. This is generally done in games where interactions are global and equilibria are isolated. In this paper, we analyze stability in contexts where interactions are local and where there are continua of equilibria. We focus on the public good game played on a network, where the set of equilibria is known to depend on the network structure (Bramoullé and Kranton, 2007), and where, as we show, continua of equilibria often appear. We provide necessary and sufficient conditions for a component of Nash equilibria to be asymptotically stable vis-à-vis the best-response dynamics. Interestingly, we demonstrate that these conditions relate to the structure of the network in a simple way. We also provide corresponding results for several dynamical systems related to the best response.
Background:
Measuring the quality and performance of health care is a major challenge in improving the efficiency of a health system. Patient experience is one important measure of the quality of health care, and the use of patient-reported experience measures (PREMs) is recommended. The aims of this project are 1) to develop item banks of PREMs that assess the quality of health care for adult patients with psychiatric disorders (schizophrenia, bipolar disorder, and depression) and to validate computerized adaptive testing (CAT) to support the routine use of PREMs; and 2) to analyze the implementation and acceptability of the CAT among patients, professionals, and health authorities.
Methods:
This multicenter and cross-sectional study is based on a mixed method approach, integrating qualitative and quantitative methodologies in two main phases: 1) item bank and CAT development based on a standardized procedure, including conceptual work and definition of the domain mapping, item selection, calibration of the item bank and CAT simulations to elaborate the administration algorithm, and CAT validation; and 2) a qualitative study exploring the implementation and acceptability of the CAT among patients, professionals, and health authorities.
Discussion:
The development of a set of PREMs on quality of care in mental health that overcomes the limitations of previous works (ie, allowing national comparisons regardless of the characteristics of patients and care and based on modern testing using item banks and CAT) could help health care professionals and health system policymakers to identify strategies to improve the quality and efficiency of mental health care.
Oath taking for senior executives has been promoted as a means to enhance honesty within and toward organizations. Herein we explore whether people who voluntarily sign a solemn truth-telling oath are more committed to sincere behavior when offered the chance to lie. We design an experiment to test how the oath affects truth telling in two contexts: a neutral context replicating the typical experiment in the literature, and a “loaded” context in which we remind subjects that “a lie is a lie.” We consider four payoff configurations, with differential monetary incentives to lie, implemented as within-subjects treatment variables. The results are reinforced by robustness investigations in which each subject made only one lying decision. Our results show that the oath reduces lying, especially in the loaded environment—falsehoods are reduced by 50%. The oath, however, has a weaker effect on lying in the neutral environment. The oath did affect decision times in all instances: the average person takes significantly more time deciding whether to lie under oath.
The understanding of ecosystem services is essential to support sustainable use and preservation of ecosystems. Coralligenous habitats, main contributors of the Mediterranean marine biodiversity, are yet understudied in term of services provided. This study presents an original small-scale approach to investigate the services provided by coralligenous habitats of a French study area consisting of two marine sites (Marseille and Port-Cros sites) in order to cover two contrasted anthropogenic pressure despite the small-scale. Our results are based on the opinions of 43 experts who ranked 15 services in terms of existence and level of importance for human well-being: supporting ecological functions were considered the most important, then provisioning and cultural services. Regulating services were considered uncertain due to a lack of knowledge. The small-scale approach highlighted a need for a referential frame to determine the existence of services (e.g. geographical and temporal scales, benefits and beneficiaries levels).
BACKGROUND:
In 2016, countries agreed on a Fast-Track strategy to "end the AIDS epidemic by 2030". The treatment and prevention components of the Fast-Track strategy aim to markedly reduce new HIV infections, AIDS-related deaths and HIV-related discrimination. This study assesses the economic returns of this ambitious strategy.
METHODS:
We estimated the incremental costs, benefits and economic returns of the Fast-Track scenario in low- and middle-income countries, compared to a counterfactual defined as maintaining coverage of HIV-related services at 2015 levels. The benefits are calculated using the full-income approach, which values both the changes in income and in mortality, and the productivity approach.
FINDINGS:
The incremental costs of the Fast-Track scenario over the constant scenario for 2017-2030 represent US$86 billion or US$13.69 per capita. The full-income valuation of the incremental benefits of the decrease in mortality amounts to US$88.14 per capita, representing 6.44 times the resources invested for all countries. These returns on investment vary by region, with the largest return in the Asia-Pacific region, followed by Eastern and Southern Africa. Returns using the productivity approach are smaller but ranked similarly across regions.
INTERPRETATION:
In all regions, the economic and social value of the additional life-years saved by the Fast-Track approach exceeds its incremental costs, implying that this strategy for ending the AIDS epidemic is a sound economic investment.
The aim of this paper is to study the interplay between long term productive investments and more short term and liquid speculative ones. A three-period lived overlapping generations model allows us to make this distinction. Agents have a portfolio decision. When young, they can invest in human capital that is a productive long term investment that provides a return during the following two periods. When young or in the middle age, they can invest in a bubble. Young individuals can also borrow on a credit market to finance the productive investment. However, the amount borrowed is limited by a credit constraint. We show that the existence of a stationary bubble raises productive investment and production when the bubleless economy is credit constrained and dynamically efficient. Indeed, young agents sell short the bubble to increase productive investments, whereas traders at middle age transfer wealth to old age. The bubble allows to relax the credit constraint. We outline that a permanent technological shock inducing either a larger return of capital in the short term or a similar increase in the return of capital in both periods raises productive capital, production and the bubble size. We use our framework to discuss the effect on the occurrence of bubbles of financial regulation and fiscal policy.
On many two-sided platforms, users on one side not only care about user participation and usage levels on the other side, but they also care about participation and usage of fellow users on the same side. Most prominent is the degree of seller competition on a platform catering to buyers and sellers. In this paper, we address how seller competition affects platform pricing, product variety, and the number of platforms that carry trade.
We review the most recent advances in distributed optimal control applied to Environmental Economics, covering in particular problems where the state dynamics are governed by partial differential equations (PDEs). This is a quite fresh application area of distributed optimal control, which has already suggested several new mathematical research lines due to the specificities of the Environmental Economics problems involved. We enhance the latter through a survey of the variety of themes and associated mathematical structures beared by this literature. We also provide a quick tour of the existing tools in the theory of distributed optimal control that have been applied so far in Environmental Economics.
