In order to draw statistical conclusions about the overall population of pulsars in the Galaxy, we have analysed a sample of 316 pulsars detected in surveys carried out at Jodrell Bank. Arecibo, Molonglo, and Green Bank. We quantify the important selection effects of each survey, and describe a statistically reliable pulsar distance scale based on a model for the large-scale distribution of free electrons in the Galaxy. The distance scale is calibrated by independent distance estimates for 38 pulsars. These results allow the spatial and luminosity distribution functions of galactic pulsars to be computed. We conclude that the Galaxy contains approximately 70000 potentially observable pulsars with luminosities above 0.3 mJy kpc2. Most of these pulsars have luminosities less than 10 mJy kpc2, more than an order of magnitude less than the mean luminosity of the observed sample. The distribution in galactocentric radius rises smoothly through the solar location towards the galactic centre and peaks inside 6 kpc, again in contrast to the observed sample which peaks near the Sun. The galactic z distribution has a scale height of about 400 pc, much larger than that of the OB stars from which pulsars form. We then consider the period and luminosity evolution of pulsars, using an approach similar to that developed by Gunn & Ostriker, and show that the observed distributions of period, period derivative and galactic z distance can be accounted for without invoking either late turn-up or an abrupt cut-off in the pulsed luminosity. The derived time constant for decay of the magnetic field is approximately 9 Myr. The pulsar birthrate required to maintain the observed population is one every 30 to 120 yr - in satisfactory agreement with the galactic supernova rate, the birthrate of supernova remnants, and the death rates of stars in the mass range generally thought to leave neutron star remnants. © 1985 Royal Astronomical Society. Provided by the NASA Astrophysics Data System.
