Only super-user can nice(1) a job

[HCART at VAX.OXFORD.AC.UK]

    When I nice(1) a job on my 3130, the command seems to have
no effect, and the job runs at the same priority as the
interactive session whatever the increment used.

    However, if I issue a nice(1) command as super-user the job is
pushed deep into the background as required.

    Why is this?  And how can I change things so that users can
nice their own jobs without being super-user?

    Hugh Cartwright.

    Physical Chemistry, Oxford University, UK.
    (HCART at vax.ox.ac.uk  or  hmc at physchem.ox.ac.uk)