arXiv subjects

Brice Magdalou

Publications and source records attributed to Brice Magdalou.

4 recordsLinked to original sources

arXiv2025

Parental environment and student achievement: Does a Matthew effect exist?

This paper investigates the causal impact of the parental environment on the student's academic performance in mathematics, literature and English (as a foreign language), using a new database covering all children aged 8 to 15 of the Madrid community, from 2016 to 2019. Parental environment refers here to the parents' level of education (i.e. the skills they acquired before bringing up their children), and parental investment (the effort made by parents to bring up their children). We distinguish the persistent effect of the parental environment from the so-called Matthew effect, which describes a possible tendency for the impact of the parental environment to increase as the child grows up. Whatever the subject (mathematics, literature or English), our results are in line with most studies concerning the persistent effect: a favourable parental environment goes hand in hand with better results for the children. As regards the Matthew effect, the results differ between subjects: while the impact of the parental environment tends to diminish from the age of 8 to 15 in mathematics, it forms a bell curve in literature (first increasing, then decreasing) and increases steadily in English. This result, which is encouraging for mathematics and even literature, confirms the social dimension involved in learning a foreign language compared to more academic subjects.

econ.GN↗

arXiv2025

DPO Unchained: Your Training Algorithm is Secretly Disentangled in Human Choice Theory (and its Loss' Convexity is Dispensable)

Normative theories allow one to elicit key parts of a ML algorithm from first principles, which is crucial at a time of championed scrutiny for ML work. Direct Preference Optimization (DPO) cleverly bypasses reward modeling by making an explicit link with a specific normative model of human choice. Our paper elevates this connection to the full generality of DPO's normative framework. Getting there requires reworking human choice theory's textbook path for a better RLHF/ML fit. It elevates the connection to a remarkably broad viewpoint on preference optimization, considering the current panorama of DPO follow-ups. It also unveils unexpected riches for ML, chief among which the support for non-convex losses, the fact that any compliant ML analytical choice can be embedded with any human choice model, and a normative framework's umbrella wide enough to safeguard DPO's extensions (margins, length correction, ...). A toy experiment ``far away'' from the DPO crowd is given.

cs.LG↗

arXiv2024

Does the Gini index represent people's views on inequality?

This paper presents findings from a web-experiment on a representative sample of the French population. It examines the acceptability of the Pigou-Dalton principle of transfers, which posits that transferring income from an individual to a relatively poorer one, reduces overall inequality. While up to 60% of respondents reject standard transfers, the three alternative transfers we test receive more approval, especially those promoting solidarity among lower-income recipients. The study then models respondents' preferences with two types of social welfare functions, utilitarian and Extended Gini. The Extended Gini model aligns better with individual preferences. Nevertheless, Extended Gini-type social welfare functions that adhere to the principle of transfers (including the one underlying the Gini index) poorly capture preferences of each individual. However, quite surprisingly, the preferences of the median individual align almost perfectly with the Gini-based function, using either parametric or non-parametric estimates.

econ.GN↗

arXiv2009

Information geometries and Microeconomic Theories

More than thirty years ago, Charnes, Cooper and Schinnar (1976) established an enlightening contact between economic production functions (EPFs) -- a cornerstone of neoclassical economics -- and information theory, showing how a generalization of the Cobb-Douglas production function encodes homogeneous functions. As expected by Charnes \textit{et al.}, the contact turns out to be much broader: we show how information geometry as pioneered by Amari and others underpins static and dynamic descriptions of microeconomic cornerstones. We show that the most popular EPFs are fundamentally grounded in a very weak axiomatization of economic transition costs between inputs. The strength of this characterization is surprising, as it geometrically bonds altogether a wealth of collateral economic notions -- advocating for applications in various economic fields --: among all, it characterizes (i) Marshallian and Hicksian demands and their geometric duality, (ii) Slutsky-type properties for the transformation paths, (iii) Roy-type properties for their elementary variations.

q-fin.GN↗