You need studies to show that peace & stability support greater productivity and wealth? Likely as it is that research can indeed confirm this, given the depth

You need studies to show that peace & stability support greater productivity and wealth? Likely as it is that research can indeed confirm this, given the depth & tone of your inquiry, perhaps the most immediate convincing experiment would be best: find someone you can employ to harass and threaten your property and your person, occasionally to devastating effect, alongside another person who can study your productivity and wealth before and after. Perhaps with further similar efforts here you can even persuade some people to volunteer for half of that project free of charge.