To repeal the Michigan Business Tax as of Jan. 1, 2016, which would actually mean revoking nearly $9 billion worth of corporate subsidies and tax breaks that were mostly granted by the Granholm administration under the repealed Michigan Economic Growth Authority program. The MBT was repealed as the state’s main business tax in 2011, and replaced by a lower corporate income tax, but it was left on the books as a “vehicle” for delivering the already-granted MEGA subsidies and tax breaks, contracts for which the current administration says it does not want to impair.   Official Text and Analysis.