We investigate the birth and evolution of Galactic isolated radio pulsars .
We begin by estimating their birth space velocity distribution from proper motion measurements of ( ) .
We find no evidence for multimodality of the distribution and favor one in which the absolute one-dimensional velocity components are exponentially distributed and with a three-dimensional mean velocity of 380 ^ { +40 } _ { -60 } km s ^ { -1 } .
We then proceed with a Monte Carlo-based population synthesis , modelling the birth properties of the pulsars , their time evolution , and their detection in the Parkes and Swinburne Multibeam surveys .
We present a population model that appears generally consistent with the observations .
Our results suggest that pulsars are born in the spiral arms , with a Galactocentric radial distribution that is well described by the functional form proposed by ( ) , in which the pulsar surface density peaks at radius \sim 3 kpc .
The birth spin period distribution extends to several hundred milliseconds , with no evidence of multimodality .
Models which assume the radio luminosities of pulsars to be independent of the spin periods and period derivatives are inadequate , as they lead to the detection of too many old simulated pulsars in our simulations .
Dithered radio luminosities proportional to the square root of the spin-down luminosity accommodate the observations well and provide a natural mechanism for the pulsars to dim uniformly as they approach the death line , avoiding an observed pile-up on the latter .
There is no evidence for significant torque decay ( due to magnetic field decay or otherwise ) over the lifetime of the pulsars as radio sources ( \sim 100 Myr ) .
Finally , we estimate the pulsar birthrate and total number of pulsars in the Galaxy .