baggingReserve: Bagging and Regression Trees for Individual Claims Reserving

Claim-level (individual) loss reserving in non-life insurance, and the means to check claim-level reserves against the payments that followed. A data contract turns a table of claims and a table of payment transactions into a claim-by-development-year panel at a valuation date; a recursion engine completes the payment history of every reported claim one development year ahead, with plugged-in means or simulated payments, for regression trees, their bootstrap aggregation (bagging) and user-supplied learners; payments for incurred-but-not-reported claims are added from chain-ladder claim counts and the average predicted payment per development year; and back-tests score a prediction and a reference method such as the chain ladder against realised payments by calendar year and component. The default estimator is the method of Janoušek and Pešta (2025) <doi:10.1007/s00362-025-01715-9>, one regression tree per development year with bagging for replicate predictions, whose spread describes the bootstrap resampling variation of the predictions of (by default unpruned) trees, and an out-of-bag diagnostic of the one-year regressions; for totals beyond next year simulated instead of plugged-in completion is recommended. Ships a reproducible synthetic individual-claims dataset generated with the individual claims simulator of Wang and Wüthrich, built on 'SynthETIC'.

Version: 0.2.0
Depends: R (≥ 4.1)
Imports: codetools, graphics, parallel, rpart, rngtools, stats, utils, withr
Suggests: ChainLadder, knitr, R.rsp, testthat (≥ 3.0.0)
Published: 2026-11-12
DOI: 10.32614/CRAN.package.baggingReserve (may not be active yet)
Author: Jan Janoušek ORCID iD [aut, cre], Michal Pešta ORCID iD [aut]
Maintainer: Jan Janoušek <janousek at karlin.mff.cuni.cz>
BugReports: https://github.com/HeirOfIsildur/baggingReserve/issues
License: GPL (≥ 3)
URL: https://github.com/HeirOfIsildur/baggingReserve
NeedsCompilation: no
Citation: baggingReserve citation info
Materials: README, NEWS
CRAN checks: baggingReserve results

Documentation:

Reference manual: baggingReserve.html , baggingReserve.pdf
Vignettes: Claim-level reserving and back-testing: a short tour (source, R code)
baggingReserve: Bagging and Regression Trees for Individual Claims Reserving in R (JSS manuscript) (source)

Downloads:

Package source: baggingReserve_0.2.0.tar.gz
Windows binaries: r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries: r-release (arm64): not available, r-oldrel (arm64): not available, r-release (x86_64): not available, r-oldrel (x86_64): not available

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