1. Given the intensity of the deficit panic that gripped Washington a few years ago, the sharp improvement in America's fiscal fortunes hasn't gotten nearly the attention you would expect. But the change has been big.

2. In July 2010, the Obama administration projected a 2020 deficit of 5.1 percent of GDP, assuming current policies continued. That's fallen by 40 percent, to 3.3 percent of GDP, in the administration's latest projections. If you prefer thinking in terms of actual dollars, it's a difference of $491 billion in 2020.

3. To put that in perspective, the Congressional Budget Office projected that the budget roadmap that Rep. Paul Ryan released in 2010 would bring deficits down to 3.7 percent of GDP by 2020. So the current projections put us below where Ryan's plan would have taken us in 2020.

4. The administration has a helpful — if ugly — chart breaking down what's happened since 2010. It's a mixture of lower health costs (more on that here), lower spending, and tax increases.

5. The White House further projects that if Congress passed all the policies in its budget into law, the deficit would fall to 2.5 percent of GDP come 2020. Another helpful, and ugly, chart shows that the further improvements would come through cuts to health spending, revenue-raising tax reform, immigration reform.

6. Seriously, White House, your charts can look nicer than this.

7. Washington doesn't much care about deficits anymore. Of course, the truth is Washington never cared all that much about deficits in the first place, including when deficits were all anyone wanted to talk about.

8. Republicans didn't care about deficits enough to accept even a dollar of tax increases in order to close them. The major concessions Democrats made were driven by fear of breaching the debt ceiling, not higher deficits. Both parties care more about the policies they actually want to pass than the abstract debt-to-GDP ratio.

9. As well they should. The most important chart in President Obama's 2016 budget isn't even in the budget proper. It's in the "Long-Term Budget Outlook" chapter of the Analytical Perspectives volume released alongside the budget and it projects the long-run deficit at different levels of productivity growth.

10. In the post-World War II period, productivity growth has hovered around 2.2 percent. Its been slower in recent years. The White House is projecting productivity growth at 1.8 percent per year — slower than the historical average. The "pessimistic" scenario lops .25 percent off that estimate. The "optimistic" scenario adds .25 percent. So the optimistic scenario is 2.05 percent — again, slower than the historical average.

11. Yet the swings here are enormous. The more optimistic case delivers deficits of less than three percent, even with no other policy changes, come 2040 — and remember, that's the same period when the Boomers are retiring and Medicare and Social Security costs are exploding. The more pessimistic case shows deficits around seven percent.

12. So even if all you care about is deficits, what you really care about is productivity and, by extension, broad economic growth. And that's where policy becomes more important than mindless exercises in budget arithmetic. We could slash R&D spending to zero and raise corporate tax rates to 70 percent and improve the deficit picture for a minute or two. But the long-term hit to growth would be huge — and the deficit would soon become a very ugly reflection of it.

13. Conversely, we could pass a sensible immigration bill into law, and make deeper, smarter investments into R&D and infrastructure, and really work on early childhood education, and get the tax code into a smarter place, and all of that would help productivity and, in the long-run, deficits.

14. But this is also why the rapidly improving deficit picture isn't getting nearly as much attention as the deficit panic of 2010-2012. The deficit panic was very useful for groups who wanted to push a lot of their (sometimes unpopular) ideas into law by hiding them in the guise of deficit reduction. Now that the deficit is less of a concern, it's less politically useful, and so there's less attention to it.