As we mentioned last week, California enacted, as part of its budget compromise, a change in the rules determining what share of a corporation's income is taxable in the state. To be specific, California adopted an optional "single sales factor" apportionment formula, which multi-state corporations support -- because it will help them avoid taxes. Virginia appears to be following suit this week. Both of the state's legislative chambers have approved optional single sales factor apportionment, though only for manufacturers. The Governor has yet to sign the measure, and he has reportedly taken no position on the bill. You can read the ITEP Policy Brief explaining how single sales factor apportionment can reduce the fairness and adequacy of state corporate income taxes here.