$10^{11.86\pm0.3}$[${\mathrm M_{\odot}\thinspace}$]{}. The best–fit value for the median mass is a factor three lower than in the massive–halo model, in which case not all of the most–massive haloes would be occupied by LBGs – leaving some space for other galaxy types.

Unfortunately the clustering results allow for more than one interpretation. As shown by Wechsler et al. (2001) an alternative model proposed by Somerville, Primack & Faber (2001; hereafter SPF), in which LBGs have lower masses but are temporarily brightened due to merger–induced star formation, predicts similarly strong clustering as the massive–halo model. In this picture the virial masses are an order of magnitude lower than in the massive–halo model, with median value of $10^{11.3}$[${\mathrm M_{\odot}\thinspace}$]{}(Primack, Wechsler & Somerville, 2003).

Finally, an indirect lower limit to the halo masses is provided by multiplying the estimated stellar masses of LBGs by the ratio of the cosmological matter density to the density in baryons ($\Omega_m/\Omega_b$). Taking the median value of the stellar mass estimated by Shapley et al. (2001), from fits to optical and near-infrared photometry, this provides a lower limit to the median halo virial mass of $10^{11.1}$[${\mathrm M_{\odot}\thinspace}$]{}.

To summarise, current estimates of the median halo virial mass of LBGs 