[kcorbitt]

But government revenue is almost certainly the wrong thing to optimize for. You probably want to optimize for something closer "wellbeing of the median citizen," although there's of course a lot of disagreement on what the actual right metric is.

This is a very practical difference. For the sake of easy math, let's assume that the maximum-revenue point on the curve is a 50% tax rate. It then follows that for every % you charge someone over 50%, tax revenue decreases. Which means that at this rate, every additional X% of tax is actually decreasing total economic output by 2X%! And assuming that we're on a smooth curve, that means that every X% you DECREASE your tax from the Laffer point is creating 2X% of economic value. Now, based on how fairly the created value is distributed and how efficiently you believe the government can spend its tax revenue you may have a different opinion on how much value you're comfortable destroying to increase tax revenue, but I'd submit that 2X is quite a high number.

I believe we need much-higher-than-0 taxes, but "we're still below the Laffer point" is a poor argument for raising them.