Tag Archives: Olivier

Publications

Selection bias in insurance: why portfolio-specific fairness fails to extend market-wide

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With Marie-Pier Côté and Olivier Côté, we recently upload a short note, selection bias in insurance: why portfolio-specific fairness fails to extend market-wide, now available on SSRN,

Fairness centres on people. In insurance, the scope of fairness should be the entire insured population, not solely an insurer’s clients. However, each insurance company’s portfolio represents a possibly skewed subsample. Models fit to these selection-biased data do not generalise well for the broader population of insureds. Two biases stem from portfolio composition: representation bias, when large prediction errors are made on individuals from subpopulations infrequently observed, and selection bias, when underwriting and marketing skew the portfolio away from the insured population. We examine how portfolio composition affects fair premium methodologies for mitigating direct and indirect discrimination on a protected attribute. We illustrate how unfairness mitigation based on a selection-biased portfolio does not yield a fair market from the perspective of insureds. Relying on causal inference and a portfolio composition indicator, we describe the selection mechanism and determine conditions under which each bias affects various fairness-adjusted premiums. We propose a method to recover the population-wide fairness-adjusted premiums from selection-biased data, by using a (third-party provided) unbiased estimate of the prohibited attribute distribution. We show that this approach effectively mitigates selection bias but leads to overall premiums that are not balanced. In a limiting case, we show that portfolio-specific fairness-aware premiums can lead to a market-wide unawareness strategy: portfolio composition opens the back door to proxy discrimination.

(to be continued…)

Seminar

Perspective causale sur les discriminations directes et indirectes liées aux caractéristiques sensibles dans les modèles prédictifs en assurance

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Olivier Côté donnera un exposé “Perspective causale sur les discriminations directes et indirectes liées aux caractéristiques sensibles dans les modèles prédictifs en assurance” au séminaire étudiant de l’IID intitulé modèles causaux et inférence causale en médecine et assurance, cet après midi

L’équité envers les assurés est un enjeu central pour le secteur de l’assurance. Les assureurs reposent largement sur les données personnelles pour plusieurs décisions automatisées. Dans ce travail, nous explorons la tarification équitable en assurance à travers une perspective causale, en mettant l’accent sur les discriminations directes et indirectes liées aux variables sensibles définies et observées. Nous analysons les mécanismes par lesquels ces variables influencent la tarification et proposons une catégorisation des méthodologies équitables en cinq familles, chacune présentant des propriétés claires en matière d’équité. Le raisonnement causal permet de représenter les biais, de clarifier les hypothèses concernant le mécanisme générateur de données, et de distinguer le signal de chaque variable par rapport aux variables sensibles.

Les outils développés guideront les spécialistes du secteur de l’assurance vers de meilleures pratiques en équité algorithmique.

Research

SCOR Project Newsletter #2

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The second newsletter, related to the SCOR research project is now available. It is a brief summary of the second six months block, from April till the end of September (the first one is available here).

As explained, over the past six months, we have had several interns, including Noé Bosc-Haddad, Florent Crouzet, Julien Siharath, Ana María Patrón Piñerez and Cassandra Mussard, the visit of Laurence Barry and Fei Huang, Philipp Ratz and Samuel Stocksieker defended their PhD, François Hu finished his postdoctoral fellowship, while Marouane Il Idrissi and Arsene Zotsa just arrived, Agathe Fernandes Machado and Olivier Côté (co-supervised with Ewen Gallic and Marie-Pier Côté) finished their PhD courses and are now 100% on their research… We wrote papers, gave talks… Thank you to all those who have supported us, and continue to support us. At least two more years to work on insurance and predictive models, fairness, calibration, discrimination, trust, explainability, interpretability, market equilibria, competition, generative models, and so much more… We’ve still got a lot of work to do, and plenty of enthusiasm!

Actuarial science, Conferences

Talk at the 27th International Congress on Insurance: Mathematics and Economics

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On Wednesday morning, I will be chairing our session “Discrimination-free Insurance Pricing” at the Insurance: Mathematics & Insurance Conference, in Chicago. With Olivier Côté, Lydia Gabric and Hong Beng Lim, we will be four speaker, just before lunch time. My talk will be a mix of recent work on quantifying and mitigating discrimination in scores (in insurance). Slides are available online.

 

Conferences

WIM (Workshop in Insurance Mathematics) is back

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After four year without it, the WIM is back. Last time, it was in February 2020. Tomorrow, Agathe and Olivier will present posters at the Workshop in Insurance Mathematics, a Concordia University.

Both posters will be on fairness and discrimination. Olivier Côté will present a poster on “Fairness in insurance enigma: exploring the maze of regulation”

Agathe will present a poster on Equipy, “A Python Package for Sequential Fairness using Optimal Transport with Applications in Insurance”

Publications

A Fair price to pay: exploiting causal graphs for fairness in insurance

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Our paper, a fair price to pay: exploiting causal graphs for fairness in insurance, writen with Olivier Côté and Marie-Pier Côté is now available,  on SSRN

In many jurisdictions, insurance companies must not discriminate on some given policyholder characteristics. Omission of prohibited variables from models prevents direct discrimination, but fails to address proxy discrimination, a phenomenon especially prevalent when powerful predictive algorithms are fed with an abundance of acceptable covariates. The lack of formal definition for key fairness concepts, in particular indirect discrimination, hinders the fairness assessment of methodologies. We review causal inference notions and introduce a causal graph tailored for fairness in insurance. Exploiting these, we discuss potential sources of bias, formally define direct and indirect discrimination, and study the properties of fairness methodologies. A novel categorization of fair methodologies into five families (best-estimate, unaware, aware, hyperaware, and corrective) is constructed based on their expected fairness properties. A comprehensive pedagogical example illustrates the practical implications of our findings: the interplay between our fair score families, group fairness criteria, and sources of discrimination.

Seminar

Talk on Fairness and Discrimination in Insurance at the Thelem-ILB Chaire

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This morning, I will be giving a talk for the Thelem-ILB Chaire (Thelem – historically compagnie d’assurance mutuelle contre l’incendie dans le département du Loiret – founded in 1820, one of France’s oldest companies), on fairness and discrimination in insurance, and more specifically on counterfactual fairness, and causal graphs. It is based on recent work with Olivier Côté, our PhD student in Laval (Québec), co-supervised with Marie-Pier,

Slides are available online. I can mention here that we obtained a grant from the Thelem-ILB Chaire to sponsor a trip in Europe for Olivier, to attend the Insurance Data Science conference in London, and the 26th International Congress on Insurance: Mathematics and Economics in Edinburgh.

Seminar

Présentation sur l’équité et la discrimination en assurance, pour Intact

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Demain matin, avec Olivier et Marie-Pier Côté, on sera chez l’assureur Intact pour parler équité et discrimination. Olivier présentera ses travaux récents sur l’utilisation de modèles causaux pour proposer des modèles “équitables” en assurance. Le papier (a fair price to pay: exploiting directed acyclic graphs for fairness in insurance) sera bientôt disponible !

Seminar

A Fair price to pay: exploiting directed acyclic graphs for fairness in insurance

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Tonight (Montréal time), Marie-Pier Côté will give a talk on “a fair price to pay: exploiting directed acyclic graphs for fairness in insurance” based on recent joint work with our PhD student, Olivier Côté, in Melbourne, Australia

Many jurisdictions have laws or guidelines stipulating that insurance companies must not discriminate on some specified policyholder characteristics. Omission of the prohibited variables from the models removes direct discrimination, but does not prevent proxy discrimination — a phenomenon especially prevalent when powerful predictive algorithms are fed with an abundance of allowed covariates. In the actuarial literature, there remains some confusion on the definition of indirect discrimination: this impedes the understanding of the goals of each fairness methodology and their comparison. In the causal inference literature, many tools, such as directed acyclic graphs (DAGs), help uncover various types of biases. A DAG describes the causal relationships between variables of interest and has clear dependence implications. We exploit this tool for fairness to formally define direct and indirect discrimination, to discuss potential sources of bias, and to understand the properties of different fairness methodologies. Four families of fair scores (best-estimate, unaware, aware and corrective) are placed in the DAG representing the insurance pricing problem. This allows us to study their behaviour in terms of direct and indirect discrimination. A comprehensive pedagogical example illustrates our findings.

More to come soon…

Conferences

Multivariate Attribute Utility and Risk

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Thursday and Friday, we organize, with Olivier, Debrah and Christoph a small workshop, at Université de Rennes 1, on Multiattribute Utility and Risk. The workshop will take place place Hoche, at the Economics faculty. Speakers are

It should be a nice informal workshop, organized with the financial support of the Actinfo Chair.
Research, Seminar

MultiAttribute Copula Utility Functions

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In June, with Olivier L’Haridon, we will organize a (small) conference, in Rennes, on risk models in a multi-attribute framework. In order to fully enjoy the workshop (more to come on the blog), we organized this year an internal workshop on that topic. A gave an oveview in September on multivariate distributions, with an emphasis on spherical / elliptical distributions, distributions on the simplex, and copulas. This time, following recent presentations made by Olivier, I will present Ali E. Abbas (recent) contributions on copula-type multriattribute utility functions. Slides are online, and the presentation will be this Thursday

As discussed in the introduction, one (nice) application can be the choice of a seat in a theatre, see