The impact of population size
On average in a year, countries publish about 1 paper for every 1000 people. If we normalize the number of published articles (as above with Olympic medals), the leaderboard changes. The US and China no longer at the top -- in fact, there are a few countries that produce around twice as many articles as the US and China on a population-adjusted basis. If we awarded medals for research publications per capita, Switzerland, Denmark and Australia would take the Gold, Silver, and Bronze.