The paper talks about economic growth, income distribution and unemployment.

I'm mostly interested in economic growth, so looked at what the paper claimed about that.

It found that major, sudden reductions in taxes on the rich did not have any statistically significant effect on the trajectory of economic growth over the following five years.

But:

- Their sample is small. They only looked at relatively large, discrete declines in their home-grown measure of taxes on the rich. They did not look at all tax-rate changes.

- They did not look at effects beyond the five-year horizon, which means it would probably exclude the impact on people starting startups, as the successful ones usually take more than 5 years to start making serious money. (or did during the period the paper considered, even if timelines have subsequently accelerated.)

- Big sudden tax cuts don't happen in a vacuum, and I don't see a way to control for confounding.

The question I have is that at some point X taxes are collected and the economy is growing at Y, then the policies change and now X-5 taxes are collected and the economy grows at Y. What was the function of the 5 under the first regime?