US health expenditure per capita

From 2009 to 2021, the annual sales figure for Alibaba's Singles Day shopping event grew in near-perfect correlation with US health expenditure per capita, at r of 0.97, establishing that Chinese e-commerce and American healthcare are secretly the same economic animal. The causal story tells itself: Americans spend more on healthcare, feel better, feel richer, and somehow this manifests as higher Singles Day sales in Shanghai. Alternatively, both are simply very large numbers that got larger over thirteen years, which is a less satisfying story but possibly more accurate. The actuaries and the Alibaba analysts should compare notes.

Alibaba's Singles Day grew from roughly $7 million in 2009 to over $84 billion by 2021, following an exponential growth curve as Chinese middle-class consumer spending expanded and e-commerce penetration deepened. US health expenditure per capita grew from around $8,000 to over $13,000 across the same period, driven by pharmaceutical costs, insurance premiums, and expanded coverage under the ACA. Both are products of rising prosperity in their respective economies — one measures Chinese consumer confidence, the other measures American healthcare cost inflation — and both followed upward trajectories across the same 13-year window of global economic expansion.

Two economies growing simultaneously will produce correlated metrics even when those economies have almost nothing to do with each other. The planet's aggregate wealth went up; the things wealth buys went up with it.