One of the thorniest problems in administering state corporate income taxes is how to distribute the profits of multi-state corporations among the states in which they operate. Ultimately, each corporation’s profits should be taxed in their entirety, but some corporations pay no tax at all on a portion of their profits. This problem has emerged, in part, due to recent state efforts to manipulate the “apportionment rules” that distribute such profits. This policy brief explains how apportionment rules work and assesses the effectiveness of special apportionment rules such as “single sales factor” as economic development tools.
