In ΛCDM with statistically isotropic, Gaussian initial conditions, the matter density field and its power spectrum are expected to be statistically the same in all directions on sufficiently large scales, with any hemispherical or directional variations attributable to sampling variance and survey systematics (Peebles 1980; Coles & Lucchin 2002). Yet multiple galaxy and quasar surveys, when mapped into full-sky or hemispherical power spectra, have reported hints of dipolar or hemispherical asymmetries in clustering amplitude and large-scale power that resemble the CMB power asymmetry, raising the possibility of a real preferred direction or modulation that is difficult to reconcile with the simplest ΛCDM assumptions of exact large-scale isotropy (Yoon et al. 2014; Appleby & Shafieloo 2014).