Executive clemency procedures offer an ancient but still modern mechanism for righting injustice and coping with problems arising when the judicial system fails to adjust to social needs. As the indeterminate sentence gives way to determinate sanctions and prison crowding grows acute, clemency, particularly in the form of commutation of sentences of prisoners, offers one means of adaptation to correctional population pressures. A survey of state commutation practices finds that there is wide variation in structure and policy among the states, that in general commutation is granted quite sparingly, that in response to sentencing chances states have both increased and decreased its use, and that political and practical considerations limit the use of commutation as a prison population safety valve. (Author abstract)