I will show how the observed clustering of galaxies can be used to quantify the statistical correlation between the properties of galaxies and their surrounding larger-scale environments relative to those of other physical effects. This will be illustrated with results from mock catalogs of galaxies in real and redshift-space alongwith a comparison to actual galaxy samples obtained from the Sloan Digital Sky Survey. Comparison of the environmental dependence of clustering in the mock catalogs and in real data allows one to test the assumption that environmental effects are dominated by the statistical correlation between halo mass and environment. Finally, I will show analytically how to incorporate this assumption into the halo model description of large scale structure.