Left-hand side: generalised distributions for [α/ Fe] in two metallicity intervals, −1 < [Fe/H] < −0.5 (the “plateau regime”) and −0.5 < [Fe/H] < −0.1 (the “downturn regime”). The microlensed dwarf sample is shown by blue lines, and local thick disk sample by red lines (dotted and dashed lines show the distribution if [Fe/H] shifted by minus or plus 0.20 dex, respectively). Also included are the distributions for two iron-peak elements, Cr and Ni. Right-hand side: the difference between the bulge and thick disk [X/Fe] distributions, for metallicity shifts in the range ± 0.30 dex. Agreement is reached when the difference is zero (on the y-axis).