The cross-correlation of objects selected by ALLSKY only (top) and ALLWISE only (bottom) with their respective full samples, after applying both masks to each sample (differences not due to masking). In each panel, the green points show the autocorrelation for the complete sample selected from each catalogue, and the amplitudes of power-law fits to the data are listed in the legend (using a fixed slope of −1). The ALLSKY-only sources clearly cluster more strongly than the full AS sample, and more so for the obscured sample. This is only weakly seen in the AW-only obscured sample. Some of this effect might be explained by the faint objects only selected by one catalogue lying at the higher redshift end of the full-z distribution, but the fact that the behaviour is not the same in both cases suggests additional contamination in the AS sample.