The main modes of punishment in our penal system are imprisonment, suspended imprisonment and fines, the last being the most frequently used. Fines as a mode of punishment becomes more and more popular the more it is realized that a short sentence of imprisonment often serves no useful purpose and is sometimes even harmful. Furthermore, as criminal law expands into new areas, as a means for the enforcement of administrative regulations, on public health, road traffic, national economy, etc., fines are used more since in many of these cases imprisonment is not regarded as a suitable sanction.
Every one of the known aims of the penal sanction (retribution, deterrence, resocialization in their various aspects or, possibly a mere warning can be best achieved when the sentence is inflicted upon the defendant personally. There is no point, for instance, in imprisoning another person in place of the defendant or placing another on probation. In the same way fines too should be paid by the offender and not by anyone else.
In practice, the problem of another person taking upon himself the defendant's penalty arises mainly in respect to fines, because it is not likely that one person would be willing to suffer imprisonment on behalf of another and furthermore, the means of identification used by the prison authorities makes this extremely difficult.