QUESTION 1
1. Discuss in general (without reference to a specific enrichment action) how the extent of
enrichment liability (or the quantum of the enrichment claim) will be calculated.
The extent of enrichment liability, or the quantum of the enrichment claim, is generally calculated
with the aim of ensuring fairness and balancing the interests of both the enriched and impoverished
parties1. The key principle is that the plaintiff is entitled to either the amount by which they have
been impoverished or the amount by which the defendant has been enriched, whichever is the lesser2 .
In practice, this means that each enrichment action involves an investigation into both the enrichment
of the defendant and the impoverishment of the plaintiff, with the goal of restoring what was
received. If the specific property cannot be retransferred, the impoverished party is entitled to a
payment equivalent to the lesser value of either the enrichment or the impoverishment3 .
The timing of the calculation is also an important factor. Typically, the quantum of enrichment is
determined at the time the action is instituted, or litis contestatio4 . This means that the enrichment
must still exist in the enriched party’s patrimony at the time the claim is made. Furthermore, the
defendant is not liable for any benefits they could have derived from the enrichment but did not
actually obtain5 . If the defendant's enrichment has been diminished or lost before the action is filed,
their liability is reduced or extinguished, and it is up to the defendant to prove this non-enrichment6 .
For example, if money was spent on something the defendant would not have purchased otherwise,
such as a luxury holiday, they may not be considered enriched. However, if the money was spent on
something the defendant would have bought anyway, such as household necessities, they are
considered enriched by the expenses saved7.
There are several exceptions where liability is calculated with reference to an earlier date, resulting
in increased liability. One such exception is when the defendant gains actual knowledge of their
unjustified enrichment at the expense of another8 . If the defendant is negligent in handling the
enrichment after becoming aware of it, they remain liable for the original amount1 . Liability may
also be assessed from an earlier date if the defendant should have realized that the benefit received
could later be considered unjustified enrichment, particularly if the impoverished party has made a
demand for restitution4 . In the case of mora debitoris, or default by the debtor, liability begins from
the moment the defendant falls into default regarding repayment, though this can be reduced or
extinguished if the defendant can prove that the loss would have occurred even if retransfer had been
made in a timely manner5 . Additionally, if the enriched party acts in bad faith by relinquishing or
reducing the enrichment, liability is calculated from an earlier date3 .
However, the rules for increased liability do not apply to minors. A minor's liability is restricted to
the amount of their enrichment at the time of litis contestatio1. They are generally not liable for any
property lost or money spent before this point, except for money spent on necessities, which is
considered enrichment by saved expenses8.
When it comes to property, the impoverished party is entitled to the retransfer of property if it still
exists and is owned by the enriched party9. If the property has been sold to an innocent third party,
the claim will be for the residual value left in the enriched party's estate. If the delivered property is
worth more than what was paid for it, the impoverished party is required to pay the enriched party
the excess value, in line with the principle that the impoverished party cannot receive more than they
have been impoverished8.