[hobbyjogger]

That line in the summary is a bit misleading. The authors didn't find a "bug" in any law - instead they found a corner case that wasn't coverred by an online tool hosted by the French government to estimate family benefits under French law:

> After close inspection of the OpenFisca code, a discrepancy was located with the Catala implementation. Indeed, according to article L755-12 of the Social Security Code, the income cap for the family benefits does not apply in overseas territories with single-child families. This subtlety was not taken into account by OpenFisca, and was fixed after its disclosure by the authors.

Here's the pull request for their fix to the benefits simulator: https://github.com/openfisca/openfisca-france/issues/1426