Measurement Error and Own Goals at Euro 2020
This article was written by Alex Krumer and James Reade.
Alongside the partially full stadiums and seemingly endless streams of substitutions, another of the standout features of this European Championships has been the number of own goals. At a record level of 11, this is apparently as many during as in the entire history combined. Is this really true though, or is it a case of changing the goalposts, statistically speaking?
Consider this analogy. The original iPhone cost $499 in 2007, while in 2017 an iPhone X would have set you back in excess of a thousand dollars. If we attributed all of that increase in price to the extra demand for an iPhone now relative to 2007, we would commit an error — the iPhone X is a much more sophisticated device than its original predecessor. But how much is demand and supply, price markups, and how much is reflective of the huge changes in quality over the last 15 years?
Now, let’s go to back the own goals’ phenomenon in Euro 2020. Eleven in the tournament, and nine in all the previous European Championships all together. However, the question is whether the comparison over time is correct? Just as an iPhone in 2007 is very different to an iPhone in 2021, was an own goal in 1992 the same as an own goal in 2021?
Over the years, the definitions of own goals has changed. For example, in Euro 1992, the then captain of the Scottish national team, Paul McStay, scored the first goal in Scotland’s 3–0 win over the Commonwealth of Independent States (which replaced the USSR in that tournament). McStay’s opener went in off Dmitri Kharin’s back. The goal is very similar to the one that was scored in the game between Slovakia and Poland in the current tournament. In 1992 it was McStay’s goal. In 2021 it is an own goal by the Polish goalkeeper Wojciech Szczęsny. See https://youtu.be/c_97Gc7Wp9w?t=204 for the 1992 YouTube footage.
In the same way, the most recent own goal in Euro 2020 was scored by the Swiss player Denis Zakaria. In this case, the Jordi Alba’s strike deflected off Denis Zakaria for Spain’s opener against Switzerland. Again, very similar goals were scored in the previous tournaments. For example, Balázs Dzsudzsák from Hungary benefitted twice from deflections that changed the trajectory of the ball in the UEFA-2016 game between Hungary and Portugal. Similarly, Daniele De Rossi’s free kick went in after a deflection in the Euro 2008 game between Italy and France. However, these goals were not counted as own goals. See https://youtu.be/k5FQ9hp7jk8?t=603 for the 2008 goal.
So, rather than an unprecedented spate of own goals, it seems we have here a case of measurement error. Thus, as we need to compare like-for-like iPhones from the example earlier, so we need to compare all the goals to the current definition. In our evaluation of what is an own goal, we applied a similar methodology to the one used in Euro 2020. After watching again all the goals that were scored in the previous European Championships and applying similar rules as in the current European Championship, we found 19 own goals and not 9 as is currently being presented in media.
Below, we present all the goals that we think should count as own goals. It is important to note that the definitions are subjective and hence debatable. For example, many studies have shown different biases in subjective evaluation of professional judges in a variety of sports from football to ski jumping. However, even if there the metric is disputable, the same metric applied in Euro 2020 to count own goals should be applied in all previous tournaments, just like economists have to take care of technological advances in order to see real changes in the price of an iPhone. There has been a lot of own goals in Euro 2020, it’s not larger than in all previous tournaments.
1. A goal of Holland against Czechoslovakia at 0:0 in Euro-1976 https://youtu.be/W8JbkWSx7Fs?t=15
2. A goal of Belgium against Yugoslavia at 0:0 in Euro-1984 https://youtu.be/61XmdY8wFr8?t=33
3. A goal of Denmark against Yugoslavia at 0:0 in Euro-1984 https://youtu.be/61XmdY8wFr8?t=132
4. A goal of Germany against Scotland at 0:0 in Euro-1992 https://youtu.be/c_97Gc7Wp9w?t=204
5. A goal of Scotland against CIA at 0:0 in Euro-1992 https://youtu.be/c_97Gc7Wp9w?t=289
6. A goal of Scotland against CIA at 1:0 in Euro-1992 https://youtu.be/c_97Gc7Wp9w?t=304
7. A goal of France against Bulgaria at 1:0 in Euro-1996 https://youtu.be/KZ2InDNQ7XA?t=286
8. A goal of Holland against Yugoslavia at 2:0 in Euro-2000 https://youtu.be/Gv8iElE6AEk?t=1117
9. A goal of France against Croatia at 0:0 in Euro-2004 https://youtu.be/tFxP-FjJSFc?t=131
10. A goal of Holland against Portugal at 0:2 in Euro-2004 https://youtu.be/tFxP-FjJSFc?t=626
11. A goal of Turkey against Switzerland at 1:1 in Euro-2008 https://youtu.be/k5FQ9hp7jk8?t=147
12. A goal of Italy against France at 1:0 in Euro-2008 https://youtu.be/k5FQ9hp7jk8?t=603
13. A goal of Croatia against Ireland at 1:1 in Euro-2012 https://youtu.be/fefGWJjXxVI?t=573
14. A goal of Sweden against England at 0:1 in Euro-2012 https://youtu.be/fefGWJjXxVI?t=865
15. A goal of Sweden against Ireland at 0:1 in Euro-2012 https://youtu.be/bx2jzdx-S18?t=675
16. A goal of Hungary against Iceland at 0:1 in Euro-2016 https://youtu.be/bx2jzdx-S18?t=884
17. A goal of Hungary against Portugal at 1:1 in Euro-2016 https://youtu.be/bx2jzdx-S18?t=930
18. A goal of Hungary against Portugal at 2:2 in Euro-2016 https://youtu.be/bx2jzdx-S18?t=956
19. A goal of Wales against Northern Ireland at 0:0 in Euro-2016 https://youtu.be/bx2jzdx-S18?t=1147
Additional readings:
Gallo, E., Grund, T. and Reade, J., 2013. Punishing the foreigner: implicit discrimination in the Premier League based on oppositional identity. Oxford Bulletin of Economics and Statistics, 75(1), pp.136–156.
Garicano, L., Palacios-Huerta, I. and Prendergast, C., 2005. Favoritism under social pressure. Review of Economics and Statistics, 87(2), pp.208–216.
Krumer, A., Otto, F. and Pawlowski, T., 2020. Nationalistic bias among international experts: Evidence from professional ski jumping. The Scandinavian Journal of Economics, forthcoming.
Zitzewitz, E., 2006. Nationalism in winter sports judging and its lessons for organizational decision making. Journal of Economics & Management Strategy, 15(1), pp.67–99.
