Merger fraction f_m as a function of redshift and selection in B band luminosity, panel a) for M_B ≤ − 20 galaxies, panel b) for M_B ≤ − 19.5 galaxies, and panel c) for M_B ≤ − 19 galaxies. The orange stars are from the ALHAMBRA photometric survey (this work), the green squares from spectro-photometric pairs in GOODS-S (LS10), and the red symbols are from spectroscopic surveys: Hexagons from the SSRS2 (Patton et al. 2000), inverted triangles form the MGC (LS10), diamonds from the CNOC2 (Patton et al. 2002), dots from the VVDS-Deep (this work), triangles from the DEEP2 (Lin et al. 2004), and pentagons from Lin et al. (2008). The dashed lines are the best fit of Eq. (25) to the data. The power-law index from the best fit is labelled in the panels.