An article entitled "Fifty States, a Thousand New Tax Laws," in Inc. Magazine cites the "increasing gulf between the ways the states calculate your tax bill and the way that the Internal Revenue Service does." The article notes how "since the federal income tax was established, the states followed Washington D.C.'s lead concerning how to tax people and businesses. That ended in 1981, when 21 states adopted their own rules on depreciation in response to a Reagan tax cut .... When Congress began slashing federal rates in 2001, many cash-strapped state legislatures opted to go their own way once again."
"Tax experts call this practice 'decoupling.' States are increasingly 'decoupling' their tax codes from the federal government's. The two key area of divergence between the Fed and the states are depreciation and estate taxes" .... "The states can always raise tax rates, but they don't like having to say that they're raising rates. Decoupling makes it easier to mask an increase in taxes," says Alan Kaden, a tax attorney at the firm Fried, Frank, Harris, Shriver & Jacobson LLP in Washington D.C. "As revenues become scarcer and states are under pressure, more will do this."