This week, former GOP vice presidential nominee and current House Budget Committee Chairman Paul Ryan will present the 2013 Republican budget proposal. Unlike his last plan which didn't balance the budget until 2038, this time Ryan insists he will hit break even in just 10 ten years. As Ezra Klein explained, Ryan will close much of the shortfall by doing nothing. That is, in addition to inheriting a rosier CBO assessment which estimates the next decade's debt will be $800 billion lower than previously forecast, the new GOP blueprint, the new GOP keeps all of the $800 billion in tax revenue from the Affordable Care Act and the recent "fiscal cliff" deal. And as in his previous budgets, Ryan also pockets the $716 billion in Medicare savings he and his running mate Mitt Romney denounced last year.
But another key to Ryan's budgetary magic will almost certainly be the same tax code sleight of hand he performed in 2011 and 2012. That is, the "courageous" Paul Ryan will claim trillions in savings over the next decade by closing some of the trillion-plus dollars Uncle Sam loses in each year in tax breaks, loopholes and other expenditures. He just won't identify which ones.

As you may recall, the 2012 version of Ryan's budget which garnered the votes of 98 percent of Republicans in Congress would deliver a massive tax cut windfall for the rich, a multi-trillion giveaway offset only in part by gutting the social safety net Ryan pretends to protect. The Ryan blueprint ends Medicare as we know it with a "premium support" gambit that would dramatically shift health care costs to America's seniors. His call for repealing the Affordable Care Act could leave up to 48 million more people without health insurance. Even as his draconian austerity budget would increase unemployment beginning next year, Ryan would nevertheless ratchet up defense spending. And despite his repeated pledges to end many tax loopholes and deductions to fund his gilded-class giveaway, Ryan has been too cowardly to say which ones. As a result, this supposed deficit hawk would actually have added trillions more in red ink to the national debt.

As it turns out, there's a simple problem with Ryan's bragging that his plan will "prevent an explosion of debt from crippling our nation and robbing our children of their future." That is, his math doesn't work. As the Washington Post's Ezra Klein explained last March, Ryan has a roughly $6 trillion hole to fill:

The Tax Policy Center looked into the revenue loss associated with House Budget Chairman Paul Ryan's plan to cut the tax code down to two rates of 10 percent and 25 percent. They estimate the changes would raise $31.1 trillion over 10 years, or 15.4 percent of GDP. That's $10 trillion less than the tax code would raise if the Bush tax cuts were allowed to expire, and $4.6 trillion less than it would raise if all of the Bush tax cuts were extended.
The Republican congressman says he'll "broaden the tax base to maintain revenue...consistent with historical norms of 18 to 19 percent." So let's say Ryan needs to find close-enough deductions and loopholes to hit 18.5 percent of GDP. That means he'd need to close about $6.2 trillion in tax deductions and loopholes over 10 years.

But so far, Rep. Ryan has refused to answer the $6 trillion question: which tax deductions and loopholes will he close?

As the Washington Post showed (chart above), the trillion-plus dollars in annual tax expenditures is now larger than Uncle Sam's take from the income tax each year. And as the Post also highlighted last year, "ever-increasing tax breaks for U.S. families eclipse benefits for special interests."
It's important to understand that much of the estimated $1.3 trillion in annual tax expenditures in 2015 (a figure larger than the entire 2012 budget deficit and equivalent to about a third of the $3.8 trillion in federal spending next year) benefit working and middle income Americans. For example, the home mortgage tax deduction was worth $89 billion in 2011. Tax-deferred 401K accounts cost the Treasury $63 billion. The Earned Income Tax Credit had a similar $63 billion price tag last year.

So what deductions and loopholes are actually in the mystery meat that is Paul Ryan's budgetary dog food? As Paul Krugman explained in "Pink Slime Economics":

We're talking about a lot of loophole-closing. As Howard Gleckman of the nonpartisan Tax Policy Center points out, to make his numbers work Mr. Ryan would, by 2022, have to close enough loopholes to yield an extra $700 billion in revenue every year. That's a lot of money, even in an economy as big as ours. So which specific loopholes has Mr. Ryan, who issued a 98-page manifesto on behalf of his budget, said he would close?
None. Not one. He has, however, categorically ruled out any move to close the major loophole that benefits the rich, namely the ultra-low tax rates on income from capital. (That's the loophole that lets Mitt Romney pay only 14 percent of his income in taxes, a lower tax rate than that faced by many middle-class families.)

As Matthew Yglesias pointed out, in Ryan's 13-page description of his tax reform vision, those politically tough choices are completely missing:

Thirteen pages dedicated to explaining his vision for revenue-neutral tax reform. And even so he manages to not name a single tax deduction that he's planning to eliminate. Home mortgage interest deduction? I dunno. Electric vehicle tax credit? I dunno. Deductibility of state and local income taxes? I dunno.

Ryan has admitted as much. Appearing on MSNBC's "Morning Joe" last March 20th, Congressman Ryan declared he would "Get rid of the special interest loopholes, special deductions, lower everybody's tax rates, bring in at least as much revenue to the government but grow the economy and create jobs, and get spending under control so we can pay off this debt." But when host Joe Scarborough asked "Which one of those [loopholes] do you eliminate," Ryan decided discretion was the better part of valor (starting around the 1:15 mark):

"We want to do this in the light of day and in front of everybody. So the Ways and Means Committee, which is in charge of the tax system, sent us the plan here, which is a 10 and 25 percent bracket for individuals and small businesses, and then they want to have hearings and, in light of day, show how they would go about doing this."

Appearing on CBS Face the Nation just days later, Ryan again claimed that "We're proposing to keep revenues where they are, but to clear up all the special interest loopholes, which are uniquely enjoyed by higher income earners, in exchange for lower rates for everyone." But he once again pleaded the Fifth when asked which "special interest loopholes" he would do away with:

"That's what the Ways & Means Committee is supposed to do. That's not the job of the Budget Committee," Ryan said on Fox News Sunday. "What we're saying is, we want to do this in the light of day, not in some backroom deal. We want to have hearings in the Ways & Means Committee that Chairman Dave Camp has already started that work, to say what tax benefits should go."

For his part, Ryan has claimed - but not detailed how - he would leave "middle-income tax write-offs" in place.

Instead, he told ABC's This Week earlier this year, "With respect to the wealthy, we're saying, 'Stop subsidizing the wealthy. Close the tax shelters and loopholes that are disproportionately used by the wealthy so that we can get more tax revenue by having a broader tax base with lower rates.'" As Fox News dutifully reported:

But Ryan argued that popular deductions might not have to be eliminated for everybody -- just the high-income earners who "disproportionately" use them. He indicated a willingness to end the home mortgage interest deduction and other breaks for top earners...
Ryan said it's "impossible" to know whether the wealthy would end up benefiting more or less from all these changes.

Actually, it's not impossible. As the Tax Policy Center (TPC) and the Center on Budget and Policy Priorities (CBPP) found in their analyses of the similar Romney and Ryan proposals, only the richest households would see a lower tax bill while everyone else paid more.
Of course, Paul Ryan will doubtless defend his regressive tax plan that magically balances the budget in ten years by claiming he hasn't specified which tax breaks he would end. Which is exactly the point. Until he stops pretending the dog ate his homework, Paul Ryan's balanced budget is just a cheap trick.