How does the deduction for state and local taxes work ...

State and local income and real estate taxes make up the bulk of total state and local taxes deducted (about 60 percent and 35 percent, respectively), while sales taxes and personal property taxes account for the remainder. The state and local tax (SALT) deduction is one of the largest federal tax expenditures, with an estimated revenue cost of $96 billion in 2017 and $1.3 trillion over the...