1. An apparatus comprising: a memory device comprising population information and a plurality of migration factors stored therein, wherein the population information comprises information about population distribution across a plurality of classifications, and wherein each of the plurality of migration factors corresponds to a particular classification of the plurality of classifications and indicates how population members of the particular classification migrate to other classifications over a particular time period; and a processor communicably coupled to the memory device and configured to use the migration factors and the population information to forecast changes in the population distribution across each of the plurality of classifications over multiple time periods.