Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
The determination of public tuition fees in a mixed education system: A majority voting modelHejer Lasram et Didier Laussel, Journal of Public Economic Theory, Forthcoming

We study the determination of public tuition fees through majority voting in a vertical differentiation model where agents' returns on educational investment differ and public and private universities coexist and compete in tuition fees. The private university offers higher educational quality than its competitor, incurring higher unit cost per trained student. The tuition fee for the state university is fixed by majority voting while that for the private follows from profit maximization. Then agents choose to train at the public university or the private one or to remain uneducated. The tax per head adjusts in order to balance the state budget. Because there is a private alternative, preferences for education are not single-peaked and no single-crossing condition holds. An equilibrium is shown to exist, which is one of three types: high tuition fee (the “ends” are a majority), low tuition fee (the “middle” is a majority), or mixed (votes tie). The cost structure determines which equilibrium obtains. The equilibrium tuition is either greater (majority at the ends) or smaller (majority at the middle) than the optimal one.

Size distributions reconsideredChristian Schluter et Mark Trede, Econometric Reviews, pp. 1-16, Forthcoming

We consider tests of the hypothesis that the tail of size distributions decays faster than any power function. These are based on a single parameter that emerges from the Fisher–Tippett limit theorem, and discriminate between leading laws considered in the literature without requiring fully parametric models/specifications. We study the proposed tests taking into account the higher order regular variation of the size distribution that can lead to catastrophic distortions. The theoretical bias corrections realign successfully nominal and empirical test behavior, and inform a sensitivity analysis for practical work. The methods are used in an examination of the size distribution of cities and firms.

Country Factors and Investment Decision-Making Process of Sovereign Wealth FundsJeanne Amar, Bertrand Candelon, Christelle Lecourt et Zhou Xun, Economic Modelling, Forthcoming

We examine in this paper the complex decision-making processes that lead to investment location choice of Sovereign Wealth Funds (SWFs). Using a two-tiered dynamic Tobit panel model, we find that country-level factors do not have the same impact on the investment decision and the amount to invest and that SWFs tend to invest more frequently and with higher amounts in countries in which they already have invested. More specifically, we find that SWFs prefer to invest in countries with higher political stability, whereas they are more prone to investing for large amounts in countries that are less democratic and more financially opened. Our results also lend support to the idea that SWFs are prudent in the choice of target country concerning their investment decision but behave as more opportunistic investors concerning the amounts to be invested.

Growth and agglomeration in the heterogeneous space: a generalized AK approachRaouf Boucekkine, Giorgio Fabbri, Salvatore Federico et Fausto Gozzi, Journal of Economic Geography, Forthcoming

We provide with an optimal growth spatio-temporal setting with capital accumulation and diffusion across space in order to study the link between economic growth triggered by capital spatio-temporal dynamics and agglomeration across space. We choose the simplest production function generating growth endogenously, the AK technology but in sharp contrast to the related literature which considers homogeneous space, we derive optimal location outcomes for any given space distributions for technology (through the productivity parameter A) and population. Beside the mathematical tour de force, we ultimately show that agglomeration may show up in our optimal growth with linear technology, its exact shape depending on the interaction of two main effects, a population dilution effect versus a technology space discrepancy effect.

A Community Based Program Promotes SanitationMaria Laura Alzua, Habiba Djebbari et Amy J. Pickering, Economic Development and Cultural Change, Forthcoming
Mixed-asset portfolio allocation under mean-reverting asset returnsCharles-Olivier Amédée-Manesme, Fabrice Barthélémy, Philippe Bertrand et Jean-Luc Prigent, Annals of Operations Research, pp. 1-34, Forthcoming

Standard results about portfolio optimization suggest that the allocation to real estate in a mixed-asset portfolio should be around 15–20%. However, the institutional investors share in real estate is significantly smaller, around 7–9%. Many researches have addressed this point even if as of today no consensus has emerged. In this paper, we built-up an allocation model that can explain the empirical observed weights. For this purpose, we account for the term structure of all standard financial assets and also of real estate asset class (expected returns, volatilities and correlations depending on the time to maturity). We propose a dynamic portfolio optimization model that allows analyzing portfolio weights with respect to the whole term structure modelling, due to its tractability and its good fit when being adequately calibrated. In this framework, we provide explicit and operational solutions to the dynamic mixed-asset portfolio allocation (cash, real estate, stock and bond). The results show that accounting for investment horizon and mean-reverting dynamics allows to better examine how portfolio allocations depend on both risk aversion and investment horizon.

Corporate Cash and EmploymentPhilippe Bacchetta, Kenza Benhima et Celine Poilly, American Economic Journal: Macroeconomics, Forthcoming

In the aftermath of the U.S. financial crisis, both a sharp drop in employment and a surge in corporate cash have been observed. In this paper, based on U.S. data, we argue that the negative relationship between the corporate cash ratio and employment is systematic, both over time and across firms. We develop a dynamic general equilibrium model where heterogenous firms need cash and external liquid funds in their production process. We analyze the dynamic impact of aggregate shocks and the cross-firm impact of idiosyncratic shocks. We show that external liquidity shocks generate a negative comovement between the cash ratio and employment, as documented in the data.

Empirical evidence on the long and short run determinants of health expenditure in the Arab worldKarim Barkat, Raschid Sbia et Youcef Maouchi, The Quarterly Review of Economics and Finance, Forthcoming

This paper empirically examines the determinants of health care spending for 18 Arab world countries for the period 1995–2015 by using recently developed panel cointegration techniques. We conducted the same estimations for 3 sub-samples, namely high-income, upper-middle- and lower-middle-income countries to reduce the heterogeneity among them. Our empirical findings demonstrate that health care expenditure and its determinants are non-stationary, and revealed the existence of a long run relationship among variables. Furthermore, the estimation results suggest that income is not the only driver of health expenditure in the Arab world countries in the long run. Other variables such as medical progress and ageing population are also playing an important role in the increase of health care expenditure with major policy implications for the region in the long run. Furthermore, the results support that health care expenditure is a necessity good for the three income groups. Finally, the Pairwise Dumitrescu-Hurlin panel causality test shows evidence of a bidirectional causal relationship between health care expenditures and income for the full sample, as well as for the groups income.

Enquête sur les libertés et l’égalité : Tome 2 : Théories et prolongements - Volume 3Philippe Grill, E-conomiques, forthcoming, 569 pages, Forthcoming

Le projet de Philippe Grill est d’enquêter sur les origines et les fondements des doctrines et théories relatives aux libertés et à l’égalité. Son approche est proprement philosophico-économique, au sens où elle s’appuie sur l’une et l’autre discipline. Cette exploration conceptuelle des théories économiques et philosophiques, des hypothèses qui les fondent, des notions qui les irriguent, ou encore des masses de données empiriques aux interprétations multiples, voire contradictoires, se révèle cruciale car c’est à partir de ces doctrines et théories que sont conçues et promues les organisations sociales et les politiques publiques qui déterminent « dans quel monde on vit », en décrétant le possible et l’impossible en ces domaines. L’ouvrage contribue ainsi pleinement aux débats actuels d’éthique sociale en fournissant les moyens de définir ce que pourrait être une organisation sociale « humaniste ».
En effet, si l’on veut changer le monde, il faut le comprendre… Sereinement, pédagogiquement, c’est notamment à cette compré­hen­sion maximale que nous invite Philippe Grill. La somme encyclopédique qu’il nous propose déploie le panorama d’une philosophie économique où sont convoqués les savoirs contemporains issus de nombreuses disciplines (outre les sciences économiques bien sûr, les autres sciences sociales, la logique, l’épistémologie, les sciences cognitives, les neurosciences, la biologie de l’évolution, etc., ainsi que les engagements ontologiques des nombreux penseurs que l’ouvrage étudie). Ici, point de simple juxtaposition de disciplines, mais une architecture des connaissances qui veut montrer que les conceptions idoines sont nécessairement connexes si l’on entend démêler l’écheveau d’un homo œconomicus authentique, renversant le modèle factice que rabâchent les propagandistes de vulgates économiques outrancièrement simplistes et irréalistes. Ainsi, ce livre est un puissant levier de ce mouvement salutaire.

Enquête sur les libertés et l’égalité : Tome 2 : Théories et prolongements - Volume 2Philippe Grill, E-conomiques, forthcoming, 569 pages, Forthcoming

Le projet de Philippe Grill est d’enquêter sur les origines et les fondements des doctrines et théories relatives aux libertés et à l’égalité. Son approche est proprement philosophico-économique, au sens où elle s’appuie sur l’une et l’autre discipline. Cette exploration conceptuelle des théories économiques et philosophiques, des hypothèses qui les fondent, des notions qui les irriguent, ou encore des masses de données empiriques aux interprétations multiples, voire contradictoires, se révèle cruciale car c’est à partir de ces doctrines et théories que sont conçues et promues les organisations sociales et les politiques publiques qui déterminent « dans quel monde on vit », en décrétant le possible et l’impossible en ces domaines. L’ouvrage contribue ainsi pleinement aux débats actuels d’éthique sociale en fournissant les moyens de définir ce que pourrait être une organisation sociale « humaniste ».
En effet, si l’on veut changer le monde, il faut le comprendre… Sereinement, pédagogiquement, c’est notamment à cette compré­hen­sion maximale que nous invite Philippe Grill. La somme encyclopédique qu’il nous propose déploie le panorama d’une philosophie économique où sont convoqués les savoirs contemporains issus de nombreuses disciplines (outre les sciences économiques bien sûr, les autres sciences sociales, la logique, l’épistémologie, les sciences cognitives, les neurosciences, la biologie de l’évolution, etc., ainsi que les engagements ontologiques des nombreux penseurs que l’ouvrage étudie). Ici, point de simple juxtaposition de disciplines, mais une architecture des connaissances qui veut montrer que les conceptions idoines sont nécessairement connexes si l’on entend démêler l’écheveau d’un homo œconomicus authentique, renversant le modèle factice que rabâchent les propagandistes de vulgates économiques outrancièrement simplistes et irréalistes. Ainsi, ce livre est un puissant levier de ce mouvement salutaire. Moins