  The aim of this article is to draw attention to the importance of the
electric current loss in the energy output of radio pulsars. We remind that
even the losses attributed to the magneto-dipole radiation of a pulsar in
vacuum can be written as a result of Ampere force action of the electric
currents flowing over the neutron star surface (Michel 1991, Beskin, Gurevich &
Istomin 1993). It is this force that is responsible for the transfer of angular
momentum of a neutron star to an outgoing magneto-dipole wave. If a pulsar is
surrounded by plasma, and there is no longitudinal current in its
magnetosphere, there is no energy loss (Beskin, Gurevich & Istomin 1993,
Mestel, Panagi & Shibata 1999). It is the longitudinal current closing within
the pulsar polar cap that exerts the retardation torque acting on the neutron
star. This torque can be determined if the structure of longitudinal current is
known. Here we remind of the solution by Beskin, Gurevich & Istomin (1993) and
discuss the validity of such an assumption. Finally, it is shown that the
behaviour of the recently observed "part-time job" pulsar B1931+24 can be
naturally explained within the model of current loss while the magneto-dipole
model faces difficulties.
