Michigan's Proposal A promise has never materialized...and nothing is being done about it.

America’s Most Financially Disadvantaged School Districts and How They Got that Way | Center for American Progress

"In some states, state aid plays a much greater role in financing local public school districts, but even larger shares of such funding do little to advance equity or accommodate student needs. Michigan and Arizona are two egregious examples. Figure 6 (page 16 of the full report) conveys the pattern of revenue disparities for Michigan school districts. Since the early 1990s, Michigan has been touted as a model of state school finance reform, attempting to dramatically reduce—and, originally, to entirely eliminate— the role of property taxes for school funding and promising to pay the bulk of education costs through a statewide formula. The promise of Michigan’s school finance reforms was never realized, largely because the state found that it could not raise sufficient revenue from other tax sources to provide adequate funding for all districts.15 Instead of rethinking the original plan and better targeting the revenue that was raised to the districts that needed it most, however, the state moved forward with a plan that continued to flatly allocate aid regardless of need or local capacity to supplement."