Over at CAP, Sarah Ayres and Michael Linden have a post about how much the Simpson-Bowles plan proposes to increase revenues (i.e. taxes). The press usually reports it as $1.2 trillion, they say, but the real number is $2.7 trillion. Why the difference? It depends on what timeframe you use (eight years vs. ten years), your baseline (current law vs. current policy), and a few other things. In other words, it's complicated.
I think this is a good reason why we should all stop talking about changes in revenue and spending compared to current levels. There are just too many games you can play with that. Instead, we should simply pick a year, and then describe what happens that year under the plan in question. So we might pick, say, 2017, and report what the budget will look like under various proposals. That's much harder to fudge.
Simpson-Bowles, for example, says that in 2017 their plan produces about $3.6 trillion in revenue and $4 trillion in spending, for a deficit of $421 billion, or 2.3 percent of GDP. (It's Figure 16 in this report.) Those are the three numbers we should want to see. Obviously we're also interested in the details of how they raise revenue and cut spending, and those details might continue to be tricky to describe. But the basic figures we should be interested in aren't how much spending and taxes go up or down, which are too easy to manipulate, but simply what spending and taxes will be.
I don't imagine this is going to happen anytime soon, but I thought I'd toss it out there.