The sensitivity of the V/Vm test to uncertainties in observed parameters

A test for the uniformity of the distribution of quasars (QSOs) is based on QSO luminosity and occupied volume. The luminosity-volume test (V/Vm test) is undertaken by computing the ratio of comoving volume, V, enclosed by the distance of the QSO (assuming redshift to be cosmological) to the volume, Vm, enclosed by the QSO if it were to be on the very limit of visibility. This paper is concerned with the sensitivity of the V/Vm statistic to various parameters, taking into account cosmology, redshift, and spectral index. It is found that V/Vm can be estimated for QSos without the need for optical spectroscopy and further radio observations. Attention is also given to an extension of V/Vm to fainter magnitudes.