  We investigate the birth and evolution of isolated radio pulsars using a
population synthesis method, modeling the birth properties of the pulsars,
their time evolution, and their detection in the Parkes and Swinburne Multibeam
(MB) surveys. Together, the Parkes and Swinburne MB surveys have detected
nearly 2/3 of the known pulsars and provide a remarkably homogeneous sample to
compare with simulations. New proper motion measurements and an improved model
of the distribution of free electrons in the interstellar medium, NE2001, also
make revisiting these issues particularly worthwhile. We present a simple
population model that reproduces the actual observations well, and consider
others that fail. We conclude that: pulsars are born in the spiral arms, with
the birthrate of 2.8+/-0.5 pulsars/century peaking at a distance ~3 kpc from
the Galactic centre, and with mean initial speed of 380^{+40}_{-60} km/s; the
birth spin period distribution extends to several hundred milliseconds, with no
evidence of multimodality, implying that characteristic ages overestimate the
true ages of the pulsars by a median factor >2 for true ages <30,000 yr; models
in which the radio luminosities of the pulsars are random generically fail to
reproduce the observed P-Pdot diagram, suggesting a relation between intrinsic
radio luminosity and (P, Pdot); radio luminosities L Edot^0.5 provide a good
match to the observed P-Pdot diagram; for this favored radio luminosity model,
we find no evidence for significant magnetic field decay over the lifetime of
the pulsars as radio sources ~100 Myr.
