[영문]A recent policy change caps the annual percentage increase in the assessed value of owner?occupied homes in Cook County, Illinois. Assuming that total revenue would remain constant, the result is relief for some financed by higher taxes on others. We estimate these tax burden shifts using data on all individual parcels and individual units of government in the county. We examine other aspects of the policy. In particular, we look at some of the difficulties in using changes in aggregate tax shares for residential versus non?residential property over time to justify or analyze a policy like this.