Galaxy stellar mass functions (SMF) in four redshift bins. Top sub-panels: the SMF measured in the present study (black stars) is compared to previous measurement: Tomczak et al. (2014), pink squares; Davidzon et al. (2013), red up triangles; Moustakas et al. (2013), cyan down triangles; Ilbert et al. (2013), yellow circles; and Santini et al. (2012), green up triangles. The error bars plotted on the measures reflect different contributions to the SMF uncertainty, depending on the considered study: only Poissonian for Ilbert et al., Moustakas et al. and Davidzon et al.; Poissonian and stellar mass for Santini et al.; and Poissonian, stellar mass and cosmic variance for Tomczak et al. and the present study. The dashed line shows the SDSS-Galex local measurement of Moustakas et al. (2013). Lower sub-panels: the corresponding SMF error contributions normalised by the total SMF uncertainty (see Eq. (5)). The blue dash-dotted line represents the Poissonian contribution. The red dashed line and the cyan solid line represent the cosmic variance and the mass uncertainty contributions, respectively.