I've no doubt that Krugman is a brilliant guy, but his "takedown
" of the Paul Ryan Roadmap
was garbage. There has been some interesting back
on his analysis of the revenue side of his plan, but both supporters and detractors seem to miss the fact that that the JCT projections don't use dynamic macroeconomic modeling; in essence, their assumption is that changes in marginal tax rates have no effect on the taxable income base, which, even if you don't fully jump on the Laffer Curve
bandwagon, is obviously bullshit. The incentives for a wealthy person to game the system obviously change when we're talking about taxing 10 cents of every dollar when compared to, say 50 cents of every dollar to 75 cents of every dollar. Additionally, the very wealthy have substantially more flexibility in modulating the "on paper" aspect of their income in coordination with changes in the tax code. Aside from Krugman's admittedly minor mistake on the details of the scoring process, I haven't seen him or any of his flunkies make any attempt to address this objection.