Michigan folks passed Proposal A in the early 1990's. It was considered a form of tax relief for the home owner who, back then, has just come out of a recession and high interest rates and needed a break. A split system was created where your home (homstead) tax rate was artificially lowered by roughly 40% and a higher burden of taxation was applied to all other (non-homestead) property. Most states have a value that is multiplied times the rate to arive at a tax. In Michigan the assessor calculates a state equalized value (SEV)that is 50% of the appraised value the assessor calculates. Coupled with that is a Taxable Value upon which the taxes are actually calclulated. Over time, the taxable value increases are limited to 5% or the rate of inflation whichever is lower while the SEV climbs with the value. The more years go by the greater the disparity between the SEV and the TV. To the extent that some people may be in foreclosure after many years of living in their home, the disparity between these two numbers can be an indicator of equity. Of course, if the owner refied last year and took out 75% of his equity, the disparity might be there but the value wont. Compare the SEV and TV on the list of property and look for disparity as one way to conduct your research.