Demographer Yi Fuxian Claims China’s Population May Be Overstated by 130 Million, Puts Total at 1.27 Billion

A new monograph by Yi Fuxian, a demographer at the University of Wisconsin–Madison and a prominent critic of China’s population planning approach, contends that China may be significantly smaller than its government claims. Yi argues the country’s true population could be around 1.27 billion—far below the roughly 1.4 billion figure long cited in official statistics—implying an overcount on the order of 130 million people, about the population of Mexico.

Yi’s central claim is not merely that the number is wrong, but that the consequences of a large mismeasurement are strategic. In his telling, an inflated population total can shape national confidence and planning in Beijing, while also amplifying concerns in Washington by making China appear demographically stronger than it is.

To support his estimate, Yi leans on administrative systems that, at least in principle, should be hard to fake at scale—especially those tied to births, vaccines, and schooling. One data point he highlights involves China’s newborn tuberculosis immunization program. Under national requirements, infants are expected to receive the Bacillus Calmette–Guérin (BCG) vaccine within 24 hours after birth. Yi notes that BCG is commonly supplied in multi-dose vials that must be thrown away shortly after being opened—around 30 minutes—meaning a vial rarely translates into its labeled number of doses in real-world hospital settings. In practice, he argues, each vial yields only about 1.2 to 1.6 usable vaccinations.

Yi points to government approvals for BCG supply between 2018 and 2020, which he says ran at roughly 5.8 million vials per year. If each vial produces about 1.2 to 1.6 effective doses, that supply would correspond to far fewer vaccinations than would be needed to cover the more than 14 million births annually reported in official figures for the same period. Matching those birth totals would require each vial to immunize about 2.4 newborns on average, a rate Yi describes as medically and logistically implausible on a nationwide basis given the wastage constraints.

He also argues that the size of specific birth cohorts appears to shrink in ways that are difficult to reconcile with normal mortality or migration patterns. As an example, Yi cites the cohort born in 2000. China’s National Bureau of Statistics reported 17.7 million births that year. Yet when children from that cohort were counted at age 10 in the 2010 census, only about 14.4 million appeared. By 2015—when that group would have been reaching middle school graduation age—Yi says just about 14.2 million were recorded as completing that stage. Taken at face value, that leaves roughly 3.5 million people from a single reported birth year missing from later tallies.

Yi says his analysis is built on cross-checking multiple systems—census counts, school enrollment numbers, hospital delivery records, vaccine approvals and distribution, and household registration data. Across those sources, he argues, the pattern is consistent with systematic overstatement, not isolated reporting error.

Why it matters

If China’s population has been overstated by tens or even hundreds of millions, it would change assessments of its labor force, consumer market size, and long-term economic trajectory. It could also reshape how other countries evaluate China’s capacity and constraints, potentially altering geopolitical expectations on both sides of the Pacific. The key question to watch is whether independent audits or additional administrative datasets corroborate—or refute—the alleged gaps Yi identifies.