Why did World War One Start?

Why did World War One start? It’s a question that has always vexed historians. We wanted to bring a quantitative and probabilistic lens to the events leading up to the war, so we brought in Nate Silver, founder of FiveThirtyEight, and Tyler Cowen, famous economics blogger, to discuss.

The Verdict: While there were many factors and causes, one key point to consider with regard to Germany’s motivation was that Germany likely underestimated the probability of the other powers joining the war, and therefore the expected value of going to war was not as positive as they thought.

NATE SILVER: 

Welcome to the show, Tyler. Today we're going to be discussing the causes of World War One, and how game theory and expected value can help us understand the motivations of the major European powers that were involved.

TYLER COWEN: Yes, that's right, Nate. And one way we can analyze this is by looking at the Elo ratings of each country, which are a way to measure a country's relative strength and predict the outcome of future conflicts.

NS: Exactly. And if we look at the Elo ratings of Germany, Britain, France, Russia, the Austro-Hungarian Empire, and the Ottoman Empire in 1914, we can see that Germany was the clear leader with the highest rating. This is based on their success in previous wars, including the Franco-Prussian War, and their economic and military power.

TC: Here is a list of Elo ratings for the major powers in 1914:

Germany: 2200

Britain: 2100

France: 2000

Russia: 1900

Austro-Hungarian Empire: 1800

Ottoman Empire: 1700

NS: Right, so as we can see, Germany had a significant advantage over the other powers. However, as we know Germany and Central Powers did not end up winning the war. This likely has to do with the low Elo ratings of Austro-Hungary and the Ottoman Empire, which were not able to match the strength of the Allies.

TC: Exactly, and this is where game theory comes into play. If we look at the situation from Germany's perspective, they likely believed that they had a strong enough advantage to win the war quickly, and that the expected value of going to war was positive. However, what they didn't account for was the possibility of the other powers forming alliances and joining the war against them, which ultimately led to their defeat.

NS: Exactly, and this is where the concept of expected value comes in. The expected value of a decision is the sum of the products of the possible outcomes and their probabilities. In this case, Germany likely underestimated the probability of the other powers joining the war, and therefore the expected value of going to war was not as positive as they thought.

TC: This played out through the Schlieffen Plan, in which Germany's strategy was to quickly defeat France through a surprise attack and then turn their attention to Russia. But, as we know, this plan failed and the war dragged on for much longer than they had anticipated, ultimately leading to their defeat.

NS: And the length of World War One is a key factor to discuss. Ultimately, I don't think even Britain and France, who won the war, derived positive expected value from it, because of the length of the war and the cost in lives and damage. All powers underestimated the probability that the war would go on for so long, and therefore the expected value of going to war was not as positive as they thought.

TC: Exactly, and this is a crucial lesson for policymakers and leaders today. The decision to go to war should not be made lightly, and all possible outcomes and probabilities must be carefully considered before making such a decision.

NS: And this is where the Elo ratings and game theory can be useful tools in analyzing the motivations and decisions of countries in the lead up to war. By understanding the relative strengths and weaknesses of different countries and considering the potential outcomes and probabilities, we can gain a better understanding of why wars start and how they can be prevented in the future.

TC: Absolutely, it's always important to look at the past to understand the present and shape the future. Thank you for joining me on this discussion, Nate.

NS: Thanks for having me, Tyler. It's always a pleasure to talk with you.

TC: For our listeners, thank you for tuning in. We'll be back next week with another thought-provoking conversation.