In the previous post, I compared the tax rates under President Obama’s 2013 budget and Mitt Romney’s budget promises. But how about President Obama’s 2013 budget and the budget proposed by Paul Ryan and the House GOP?

Right now, revenues are 15.4 percent of GDP, and projected to rise, if current policies are simply extended, to 18.3 percent of GDP in 2022. Obama’s budget envisions revenues rising to 20.1 percent of GDP by then. In the Congressional Budget Office’s score (pdf) of Ryan’s budget, they projected revenues rising to 18.5 percent of GDP over the same time period.

Or let’s take debt. If current policies are extended, CBO projects public debt will rise to 94.2 percent of GDP by 2022. Obama’s budget would hold it to 76.5 percent. Ryan’s budget, according to CBO, would hold it to 70 percent. So Obama and Ryan’s budgets are fairly close on debt over the next decade.

Spending, however, is a different story. If current policies are extended, CBO estimates spending at 24.4 percent of GDP in 2022. Obama’s budget would hold it to 22.8 percent. And Ryan’s budget would keep it at 20.25 percent.

There are a few caveats to this. For one thing, the CBO looked at Ryan’s budget last April, and their economic outlook has worsened since then. If they ran the numbers on his proposal today, the dimmer economic outlook would likely lead to, at the least, more projected debt.

For another, many of Ryan’s harshest cost controls don’t kick in till well after 2022. His privatization and voucherization of Medicare, for instance. So his defenders might argue that projecting only a decade into the future unfairly cuts him off from his most radical savings, His detractors, meanwhile, could say that policies a decade into the future don’t account for much, and Ryan’s Medicare proposals are unlikely to work.

Note also that Ryan will be bringing out his 2013 budget in the coming weeks. So that will be helpful for getting a more apples-to-apples comparison.