That by itself doesn't mean much. E.g. two multi-national companies have a dispute, it'll almost certainly get filed in the U.S. instead of somewhere else. That doesn't mean Americans are more likely to sue.

Its precisely this reason (ie, learning by doing) that proves the point you're arguing against. US is the most litigous society in the world, in part because USA believes in the laws and writes them to be litigated, and second because there is such experience in litigating. Thirdly, there is a culture of blame and responsibility shifting; which the law and legal profession is just the hired-help (not the problem per-se).

you could spin it whatever way you want until the cows come home, but the data does show that on face value Entities in the US are more prolific with litigation than Entities in other nations.

Saying that 2 multi-nationals are going to duke it out in the States over the rest of the world may or may not be true - (Are a major percentage of multi-nationals headquartered in the US? If they are lodging action in the US, is it because it is easier?)

But I would tend to think that 300 Million americans and their individual actions are going to be greatly more influential on the total case load and per capita case load in the US than the approximately 70,000 multinational companies - which would be like a drop in the ocean against the individual litigations.

You make a very good point about the relative volume, you're right that individual actions are going to overwhelm the number of international business disputes (multi-nationals tend to file in the US if they can, even if they are not headquartered here, because it's has the most well-developed legal system).

That said, number of cases still does not mean that people are litigious in the sense of resorting to lawsuits instead of other available means of dispute resolution. E.g., car collisions are a huge source of litigation. The US has 3.4x as many motor vehicle deaths per capita per year as the U.K. (and presumably, many more collisions too) because of our highly suburban structure. So if we have more motor vehicle/insurance lawsuits, it doesn't necessarily mean it's because we're quicker to rely on litigation. Employment litigation is another big one for regular people. Here in the US, if you think you were fired unfairly, there is no administrative agency that'll handle the dispute. If you think you were fired because of race you can complain to the EEOC, but either way the dispute will end up in court.