They say that countries win more medals when they host the Olympics. But do they? And if so, why?
I’ve seen various theories:
Jetlag. Maybe it’s because athletes from the host country don’t need to travel as far.
Esprit de corps. Maybe athletes feel lifted up by the local crowd and try harder or feel more confident or something.
Judges. Maybe judges are biased towards local athletes.
More bites at the apple. Hosting countries are automatically able to place athletes into many events even if they wouldn’t ordinarily qualify.
New sports. Hosting countries get to propose some sports. Maybe they propose ones they are good at.
Money. Maybe when countries decide to spend billions of dollars hosting Olympics, they also spend more on finding talented athletes, giving them time to train, facilities, coaches, etc.
Which is right?
Let’s start with the data. Here are the results for all countries that have hosted the Summer Olympics since 1940. Hosting years are marked in red.
A lot of people take data like this and start screwing around with statistics. But I think it’s more informative to sweat the details a bit.
Hosts don’t always do better
They often do! But not always. Qualitatively, I see little to no bump for: Brazil, Canada, Finland, the United States (1996), and West Germany. But that means that there are bumps for the other 14/19 games. Why?
Hosts start winning before they host
Hosting countries often start getting more medals before they host. For example:
If the explanation was purely jetlag, or esprit de corps, or biased local judges, or getting to enter more athletes, or getting to pick new sports, then this wouldn’t happen. Something else is causing all those lines to go up before countries host the games. (And, often, stay up after.)
There was a boycott in 1980
One very noticeable spike in medals is for the USSR at the 1980 Olympics in Moscow. They won 195 medals, the highest total won by any country ever:
This was due to none of the causes listed above. It happened because the Soviets invaded Afghanistan and almost 70 countries boycotted the 1980s Olympics in protest, including the United States, Canada, Japan, South Korea, and West Germany. All the medals those countries didn’t win had to be won by someone. The biggest beneficiary, naturally, was the strongest country participating.
Aside: To make plots for Russia, I combined the results for the USSR before 1992, the USSR-minus-Baltics “United Team” for 1992, Russia for 1996-2014 and assorted supposedly-not-Russia-but-who-are-we-kidding teams for 2016, 2018, 2020, and 2022.
There was another boycott in 1984
Another very noticeable spike is for the United States at the 1984 Olympics in Los Angeles:
Why? The USSR and a bunch of allies boycotted these Olympics, possibly because of “anti-Soviet hysteria”, or possibly because they were annoyed about the 1980 boycott. Lots of other countries did well, too. Canada won 4 times as many medals as when they hosted the last Olympics they’d been in:
When the US hosted the Olympics again in 1996 in Atlanta, Russia showed up and there was no bump at all.
Aside: Albania—stridently communist, but seeing the Soviets as treacherous revisionists—boycotted both the 1980 and 1984 Olympics, but stressed in both cases that these were independent boycotts. Iran did something similar.
Extra athletes probably don’t win many medals
Host nations really do have many more athletes competing. This happens because athletes from the host nation can often “auto-qualify” without needing to beat other athletes in qualifying rounds. Here’s Brazil:
That had many more athletes in 2016, but it didn’t seem to do much.
More successful countries also get more athletes competing, but it’s also not clear it helps:
I’m just very skeptical how much this could help nations earn medals. If I were auto-qualified into the 400 meter dash, I could race every day for the next millennium, and I’d never place higher than last unless someone fell and broke their leg.
Maybe there are some sports with enough randomness that someone who couldn’t normally qualify has a realistic chance of winning a medal? (Skateboarding? Surfing?)
It might seem like you could directly test this theory by checking how many medals are actually won by “extra” athletes. But I think this would be quite difficult—for most sports, athletes from the host nation won’t participate in the same qualifier process, so it’s hard to say exactly who is “extra”.
It it’s jetlag, then coaches are dumb
Most teams seem to arrive weeks (and sometimes months) before the event, so they can get used to the timezone and climate. Countries spend a lot of money on trying to win medals at the Olympics. Do we really think coaches haven’t thought this through?
It’s probably not biased judges
Many events don’t have subjective scoring. But for those that do, I’m sure there is some bias. (I say this simply based on the nature of the human animal.) It wouldn’t shock me if there have been bribes paid in some cases.
But why would the bias be in favor of the host nation? The Paris gymnastics competitions are not being judged by the local middle-school gym coach. It seems that each sport has a different process for choosing judges, but they overwhelmingly seem to be international, and are typically chosen from countries that are strong in each sport.
The UK started spending money
Here’s a closer look at the medals for the United Kingdom:
The UK used to perform terribly at the Olympics. But after 1996, where they won only a single gold medal, they decided they were sick of losing. In 1997, they began funneling large amounts of money from the national lottery into Olympic athletes. They immediately started winning. Then they spent even more, and won even more. This continued until the 2012 games in London, after which funding plateaued, along with their medal count.
I tried very hard to find similar numbers for other countries, but I wasn’t able to. Please let me know if you have such data. (And let’s give the UK credit for being clear and transparent.)
Now, OK, correlation doesn’t imply causation. But come on. We have an extremely plausible mechanism here. I don’t exclude the possibility that the occasional random medal has been won because of esprit de corps. But when you spend more money on the Olympics, you can:
Test more young people to try to find talent.
Build more facilities and equipment for people to train in.
Pay for more and better coaches.
Give athletes money so they can spend all their time training rather than working. (Or going to school!)
Train many athletes in parallel, so that you have more chances someone will grow into a world-class talent years down the line.
Focus on “high ROI” sports that few people care about, but offer large numbers of medals.
Better conceal all the doping.
I don’t think this is very complicated! Medal counts are not a measure of a country’s worth. Mostly, they measure (a) population, (b) economic development, and (c) how much money you’re willing to set on fire to make numbers go up on a magic billboard.
P.S. I’ve focused on the Summer Olympics because medal counts are higher and therefore less random. But in case you’re interested, here’s data for the Winter Olympics:
Beat me to the punch! I had a post on this planned, with relevant statistical tests and data showing
- no jetlag effect (used relative longitude) and arguing like you did that teams arrive early so this shouldn't be a concern
- no climate effect (used relative latitude)
- no crowd effect (used home country ticket allotment proportions)
- an independent home advantage beyond protests
- an independent home advantage beyond possible cheating (focusing on uncheatable events)
- an independent home advantage beyond venue (using time to venue construction and events with more and less standardized venues, and athletes who live in certain countries but compete for different ones, a group I related to climate as well)
- it can't be host-specific events (advantage applies before this practice came into existence (recently) and it applies to older events)
But I guess that post isn't urgent now. Good show!
Two other possible factors:
1). Home court/field advantage. Hosting country athletes are much more likely to have familiarity with the facilities being used for the events. I can imagine this would make a big difference for outdoor sports in particular, for which the playing areas are not necessarily ‘standardized’, ie rowing in one river vs another, golf courses, tennis court surfaces etc.
2. Even in ‘objectively’ judged sports (ie basketball), referees can be influenced by the home crowd.