Evolution of the fraction of gas converted into stars for different values of the IMF used in this work. Left: evolution of the average star formation efficiency (defined as ⟨ε_⋆⟩) as a function of z. Right: evolution of the fraction of total cold gas associated with star formation (f_gas). The symbols show the measurements compiled as follows: circles by Tacconi et al. (2018), squares by Scoville et al. (2014), diamonds by Scoville et al. (2016), stars by Dessauges-Zavadsky et al. (2015), and triangles by Schinnerer et al. (2016). See also Fig. 13b of Hodge & da Cunha (2020).