In order to understand the dynamical and chemical evolution of our Galaxy i
t is of fundamental importance to study the local neighbourhood. White dwar
f stars are ideal candidates to probe the history of the solar neighbourhoo
d, since these 'fossil' stars have very long evolutionary time-scales and,
at the same time, their evolution is relatively well understood. In fact, t
he white dwarf luminosity function has been used for this purpose by severa
l authors. However, a long-standing problem arises from the relatively poor
statistics of the samples, especially at low luminosities. In this paper w
e assess the statistical reliability of the white dwarf luminosity function
by using a Monte Carlo approach.