Where does the Laffer curve bend?

Ezra Klein:

With the Bush tax cuts due to expire soon and debates about raising top rates further to cut the budget deficit soon to follow, the Laffer curve is bound to come up again. The idea, popularized by economist Arthur Laffer and writer Jude Wanninski in the 1970s and '80s, is simple. Tax rates of zero percent produce no revenue, for obvious reasons. Rates of 100 percent should produce no revenue either, as no one would bother making the money that falls into that bracket knowing it would all be taken away. Thus, presumably, there is some rate in between the two that maximizes revenue. Go above it and revenue would fall because people would avoid taxes or stop working; go below it and revenue would fall because less money would be taxed.

The Tax Experts

Emmanuel Saez, ...73% which means a top federal income tax rate of 69% (when taking into account the extra tax rates created by Medicare payroll taxes, state income tax rates, and sales taxes)...
Joel Slemrod ..."I would venture that the answer is 60% or higher.... The idea that we're on the wrong side has almost no support among academics who have looked at this....
Read Saez, Slemrod, and Seth Giertz's latest paper (PDF) on the subject.
...

Bruce Bartlett ..."Anthony Atkinson, probably the leading public finance economist in England, estimates (PDF) that the top rate could go as high as 63% to 83% before it became counterproductive in terms of revenue...The European Central Bank...finds that only two European countries are on the wrong side of the Laffer Curve. All other countries could raise substantial additional revenue by raising tax rates."

Progressive Consumption Taxes

Matthew Yglesias:

"it would be better to finance the government through a progressive tax levied on consumption... You can understand the virtues of this idea in moralistic terms (John Rawls says he prefers it “since it imposes a levy according to how much a person takes out of the common store of goods and not according to how much he contributes”) or in economic ones as laid out by Karl Smith. But what does that mean in practice? Fortunately, Dylan Matthews did a post yesterday laying out some options.

The one that’s easiest to explain, and I tend to think best, is Robert Frank’s idea. This would work exactly like the current income tax, except instead of a crazy patchwork quilt of tax-subsidies for savings you’d just exempt all savings from taxation. That would leave you with a simpler, more efficient, but less progressive tax code that also doesn’t raise adequate revenue. You need to respond by adjusting the rate structure to restore adequacy and progressivity. The resulting scheme is more conducive to long-term economic growth than our current system, equally progressive, and also somewhat simpler. And, importantly, the added simplicity doesn’t come from heroic assumptions about congress wiping away all deductions and exemptions and never putting any new ones in. It’s just simpler because it does something our tax code already does—try to encourage saving—in a simpler way.