The Headlee Amendment restricts growth in the taxable value of an individual parcel, while Proposal A requires rate reductions when the local housing market grows substantially. Proposal A limited growth on the taxable value of individual parcels to the lesser of inflation or 5%, and it reset taxable value of a property when itâs sold or transferred, which is equal to half of the propertyâs cash value. More than a decade later, some communities havenât seen property tax revenue return to 2008 levels, even though real estate values have recovered. For this reason, Michigan government leaders in December 2020 advocated for amending the relationship between the Headlee Amendment and Proposal A.