On the campaign trail, from the White House and in Congress, there’s often talk of limiting tax breaks – to raise more money or to lower tax rates or to clean up a messy tax code. Here are the 15 most expensive “tax expenditures” for individuals, based on the Joint Tax Committee’s estimates of what they’ll cost Uncle Sam in 2014 through 2018. The list includes not only deductions and income exclusions, but also refundable credits and subsidies that are wholly or partly delivered through the tax code and IRS.