Where does restitution collide?

The body of law that makes a defendant give up a gain obtained at another's expense, rather than compensate a loss: its organising idea is unjust enrichment, so the measure is what the wrongdoer got, not what the claimant went without. Birks's 1985 An Introduction to the Law of Restitution set the modern framework, treating restitution as the response the law gives when one person is enriched at another's expense in circumstances the law counts as unjust. The referent is a claim to strip and return a benefit, and it is not a number describing how a ball rebounds, nor the personal act of a wrongdoer making amends to a victim.[1]

Unit

A claim to reverse one person's gain made at another's expense

Recovery means

The remedy is the recovery: the gain is surrendered and returned, so the defendant is put back to the position before the enrichment

Measured by

Quantified by the value of the benefit the defendant received, through accounts of profits, a constructive trust, or a money award, not by the claimant's loss

In mechanics the coefficient of restitution is a number between 0 and 1 that says how much of the relative speed of two bodies survives their collision: the value is the separation speed after impact divided by the approach speed before it, so 1 is a perfectly elastic bounce that keeps all the kinetic energy and 0 is a perfectly inelastic hit that keeps none. It descends from Newton's experimental law of impact, and Cross's 2000 study in American Journal of Physics measured it for real balls and showed how it depends on speed and material. The referent is a dimensionless ratio describing a rebound, and it has nothing to do with a legal claim to return a gain or a personal act of repairing harm.[2]

Unit

A dimensionless ratio between 0 and 1 for one collision

Recovery means

The whole quantity is about recovery of speed: it names the fraction of relative velocity, and thus the square root of the kinetic energy, that the rebound restores

Measured by

Found from the ratio of separation to approach speed, or in a drop test from the square root of bounce height over drop height

In restorative justice and moral psychology, restitution is the act of making amends: an offender restores or compensates the person they harmed as part of repairing the relationship and the harm, often through an agreement reached in a meeting between the parties. Latimer, Dowden, and Muise's 2005 meta-analysis in The Prison Journal treated such restitution and reparation as core elements of restorative practices and measured their effect on victim satisfaction and reoffending. The referent is a moral and social act of repair centred on the victim's restoration, and it differs from the gain-based legal claim measured by the wrongdoer's enrichment and from the collision ratio of physics.[3]

Unit

One offender's act of amends toward the person they harmed

Recovery means

Recovery is the point: the aim is to restore the victim and the relationship, not to award a loss or reverse an unjust gain by rule

Measured by

Gauged by whether an agreed act of amends is completed and by its effects on victim satisfaction, felt repair, and later reoffending