We analyse the sample of pulsar proper motions , taking detailed account of the selection effects of the original surveys .
We treat censored data using survival statistics .
From a comparison of our results with Monte Carlo simulations , we find that the mean birth speed of a pulsar is \sim 250 - 300 km s ^ { -1 } , rather than the 450 km s ^ { -1 } found by Lyne & Lorimer ( 1994 ) .
The resultant distribution is consistent with a maxwellian with dispersion \sigma _ { v } = 190 km s ^ { -1 } .
Despite the large birth velocities , we find that the pulsars with long characteristic ages show the asymmetric drift , indicating that they are dynamically old .
These pulsars may result from the low velocity tail of the younger population , although modified by their origin in binaries and by evolution in the galactic potential .