Bicyclist traffic fatalities

As more Chinese students have studied abroad, more American cyclists have been killed on US roads, a correlation that spans continents and defies every attempt at causal explanation. The coefficient is 0.915 across ten years, during which both trends climbed steadily, suggesting that either Chinese students are terrible drivers (they are not, statistically) or that both metrics are simply measuring the growth of a globalizing, urbanizing world during the same decade. The bicycles and the student visas share a timeline but not a zip code.

Chinese students studying abroad grew from about 285,000 in 2010 to over 660,000 by 2019, driven by China's growing middle class, the prestige of Western universities, and the expansion of international student recruitment programs. US cycling fatalities grew from about 620 to over 850 during the same period, driven by urban cycling growth without corresponding infrastructure investment. Both trends peaked just before 2020 (Chinese enrollment was already declining due to visa restrictions and geopolitical tensions; cycling fatalities dipped briefly during the pandemic). The shared variable is simply the pre-pandemic decade of global expansion: more people moving, more people studying, more people cycling.

Ten years of Chinese students and American cycling deaths growing together is a reminder that in a globalizing world, any two expanding metrics will correlate if you look at them during the right decade. The students arrived, the cyclists pedaled, and the connection between them is nothing more than the sound of the 2010s happening everywhere at once. The campus and the bike lane are on different continents. The chart does not care.