I think that graph is a good example of Hauser’s Law but it really doesn’t illustrate the Laffer Curve. In fact it seems to contradict the Laffer Curve since it shows that as marginal rates decline so to does tax revenues. Unless I’m reading the graph incorrectly.
Correct; it’s Hauser’s law.
On a separate subject, do you agree that the tax wedge effect exists generally, and that increasing taxes will increase the wedge and decrease total economic activity?