The social sciences get tricky, but can still be approached scientifically. The right answer isn't simply an empirical question, because it has a lot to do with our value or political preferences. We can look at times in uas history when the tax rates have been different and we can see how the economy did under them. But there is some empirical evidence that can be brought to bear on the question. If scientists are being clear what the consensus claim is then i think, ha, it's a very powerful and important thing for us to know.