While I might be convinced this is more than coincidence, correlation is not causation. And while I don't think the author claims that it is, it certainly came across that way to me.
I think it may have more to do with similar cultural values and beliefs (institutions) other than taxation influencing the choices of the inhabitants. What do your students think? Does the author make the case that high taxes can lead to happiness? Are there other routes than through government-provided services?
I look forward to your comments.
This post relates to the following Keystone Economic Principles:
1. We all make choices.
2. There ain’t no such thing as a free lunch.
3. All choices have consequences.
4. Economic systems influence choices.
8. Quantity and quality of available resources impact living standards.