I'm trying to fashion survey experiments for which the demographic composition of the samples needs to be as close as possible to a 'golden' composition. For concreteness, let's say the 'golden' composition is
14% middle class, 35% upper-middle class, and 51% upper class.
I have a whole bunch of samples, each with slightly different compositions. For example:
S1 = 10% middle class, 41% upper-middle class, 49% upper class S2 = 33% middle class, 33% upper-middle class, 34% upper class
I'm trying to find a good statistical measure to describe how close the distribution in each sample is to the ideal, 'golden' composition. Is there a simple metric here that I could use?