With a simple evolution model of the magnetic fields of isolated radio
pulsars, the statistical evidence for them is investigated, Monte-Car
lo techniques are used to generate sample pulsars of particular distri
butions of initial periods. period derivatives, magnetic fields. lumin
osities. and Galactic positions. The period-dependent beaming fraction
of pulsars is considered in the simulation, Then the best fits by com
paring the synthesized populations with the observed pulsars are made,
It is shown that the field decay model may also have some consistency
with the current understanding of pulsar statistics.