Skip to main content
Top
Published in: European Actuarial Journal 1/2023

11-01-2023 | Letter

Model selection with Gini indices under auto-calibration

Author: Mario V. Wüthrich

Published in: European Actuarial Journal | Issue 1/2023

Log in

Activate our intelligent search to find suitable subject content or patents.

search-config
loading …

Abstract

The Gini index does not give a strictly consistent scoring function. Therefore, simply maximizing the Gini index may lead to a wrong model choice. The main issue is that the Gini index is a rank-based score that is not calibration-sensitive. We show that the Gini index allows for strictly consistent scoring if we restrict it to the class of auto-calibrated regression models. That is, on the class of auto-calibrated models we know that the true model maximizes the Gini index.

Dont have a licence yet? Then find out more about our products and how to get one now:

Springer Professional "Wirtschaft+Technik"

Online-Abonnement

Mit Springer Professional "Wirtschaft+Technik" erhalten Sie Zugriff auf:

  • über 102.000 Bücher
  • über 537 Zeitschriften

aus folgenden Fachgebieten:

  • Automobil + Motoren
  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Elektrotechnik + Elektronik
  • Energie + Nachhaltigkeit
  • Finance + Banking
  • Management + Führung
  • Marketing + Vertrieb
  • Maschinenbau + Werkstoffe
  • Versicherung + Risiko

Jetzt Wissensvorsprung sichern!

Springer Professional "Wirtschaft"

Online-Abonnement

Mit Springer Professional "Wirtschaft" erhalten Sie Zugriff auf:

  • über 67.000 Bücher
  • über 340 Zeitschriften

aus folgenden Fachgebieten:

  • Bauwesen + Immobilien
  • Business IT + Informatik
  • Finance + Banking
  • Management + Führung
  • Marketing + Vertrieb
  • Versicherung + Risiko




Jetzt Wissensvorsprung sichern!

Footnotes
1
The continuity condition is a comparably weak assumption, e.g., it suffices to have one continuous covariate component and a strictly monotone regression function in that component; see Section 2.2 of Denuit et al. [4].
 
2
In (2.2) we assume that Y has a continuous distribution \(F_Y\), otherwise the denominator in (2.2) needs to be replaced by the term \({\mathbb {E}}[|Y-Z|]/(4{\mathbb {E}}[Y])\), where Z is an independent copy of Y, see also (4.1), below. For a continuous distribution \(F_Y\) the two terms in the denominator are then equivalent.
 
Literature
2.
go back to reference Ciatto N, Verelst H, Trufin J, Denuit M (2022) Does autocalibration improve goodness of lift? Eur Actuar J, in press Ciatto N, Verelst H, Trufin J, Denuit M (2022) Does autocalibration improve goodness of lift? Eur Actuar J, in press
3.
go back to reference Denuit M, Charpentier A, Trufin J (2021) Autocalibration and Tweedie-dominance for insurance pricing in machine learning. Insurance 101:485–497MathSciNetMATH Denuit M, Charpentier A, Trufin J (2021) Autocalibration and Tweedie-dominance for insurance pricing in machine learning. Insurance 101:485–497MathSciNetMATH
4.
go back to reference Denuit M, Sznajder D, Trufin J (2019) Model selection based on Lorenz and concentration curves, Gini indices and convex order. Insurance 89:128–139MathSciNetMATH Denuit M, Sznajder D, Trufin J (2019) Model selection based on Lorenz and concentration curves, Gini indices and convex order. Insurance 89:128–139MathSciNetMATH
5.
go back to reference Denuit M, Trufin J (2021) Lorenz curve, Gini coefficient, and Tweedie dominance for autocalibrated predictors. LIDAM Discussion Paper ISBA 2021/36 Denuit M, Trufin J (2021) Lorenz curve, Gini coefficient, and Tweedie dominance for autocalibrated predictors. LIDAM Discussion Paper ISBA 2021/36
6.
go back to reference Dimitriadis T, Fissler T, Ziegel JF (2020) The efficiency gap. arXiv, 2010.14146 Dimitriadis T, Fissler T, Ziegel JF (2020) The efficiency gap. arXiv, 2010.14146
7.
go back to reference Engelmann B, Hayden E, Tasche D (2003) Testing rating accuracy. Risk 16(1):82–86 Engelmann B, Hayden E, Tasche D (2003) Testing rating accuracy. Risk 16(1):82–86
9.
go back to reference Frees EW, Meyers G, Cummings AD (2013) Insurance ratemaking and a Gini index. J Risk Insur 81:335–366CrossRef Frees EW, Meyers G, Cummings AD (2013) Insurance ratemaking and a Gini index. J Risk Insur 81:335–366CrossRef
10.
go back to reference Gini C (1912) Variabilità e Mutuabilità. Contributo allo Studio delle Distribuzioni e delle Relazioni Statistiche. C, Cuppini, Bologna Gini C (1912) Variabilità e Mutuabilità. Contributo allo Studio delle Distribuzioni e delle Relazioni Statistiche. C, Cuppini, Bologna
13.
go back to reference Lorenz MO (1905) Methods of measuring the concentration of wealth. Publ Am Stat Assoc 9(70):209–219 Lorenz MO (1905) Methods of measuring the concentration of wealth. Publ Am Stat Assoc 9(70):209–219
14.
go back to reference Menon AK, Jiang X, Vembu S, Elkan C, Ohno-Machado L (2012) Predicting accurate probabilities with ranking loss. ICML’12: Proceedings of the 29th International Conference on Machine Learning, 659–666 Menon AK, Jiang X, Vembu S, Elkan C, Ohno-Machado L (2012) Predicting accurate probabilities with ranking loss. ICML’12: Proceedings of the 29th International Conference on Machine Learning, 659–666
15.
go back to reference Newson R (2002) Parameters behind “nonparametric’’ statistics: Kendall’s tau, Somers’ D and median differences. Stata J 2(1):45–64CrossRef Newson R (2002) Parameters behind “nonparametric’’ statistics: Kendall’s tau, Somers’ D and median differences. Stata J 2(1):45–64CrossRef
17.
go back to reference So B, Boucher J, Valdez E (2021) Cost-sensitive multi-class AdaBoost for understanding driving behavior based on telematics. ASTIN Bull 51(3):719–751MathSciNetCrossRefMATH So B, Boucher J, Valdez E (2021) Cost-sensitive multi-class AdaBoost for understanding driving behavior based on telematics. ASTIN Bull 51(3):719–751MathSciNetCrossRefMATH
18.
go back to reference Somers RH (1962) A new asymmetric measure of association for ordinal variables. Am Sociol Rev 27(6):799–811CrossRef Somers RH (1962) A new asymmetric measure of association for ordinal variables. Am Sociol Rev 27(6):799–811CrossRef
19.
go back to reference Tasche D (2006) Validation of internal rating systems and PD estimates. arXiv:0606071 Tasche D (2006) Validation of internal rating systems and PD estimates. arXiv:0606071
22.
go back to reference Wüthrich MV, Merz M (2023) Statistical foundations of actuarial learning and its applications. Springer Actuarial Wüthrich MV, Merz M (2023) Statistical foundations of actuarial learning and its applications. Springer Actuarial
Metadata
Title
Model selection with Gini indices under auto-calibration
Author
Mario V. Wüthrich
Publication date
11-01-2023
Publisher
Springer Berlin Heidelberg
Published in
European Actuarial Journal / Issue 1/2023
Print ISSN: 2190-9733
Electronic ISSN: 2190-9741
DOI
https://doi.org/10.1007/s13385-022-00339-9

Other articles of this Issue 1/2023

European Actuarial Journal 1/2023 Go to the issue