Wang, M., Fuerst, J., Ren, J. (2016). Evidence of dysgenic fertility in China. Intelligence, 57, 15-24.
From the discussion: “We’ve seen, in Table 4, that urban populations in China exhibited a relatively high dysgenic fertility trend in the 1951–1970 birth cohort. For this same cohort, the trend was much smaller in the rural populations. It suggests that dysgenic selection is related to urbanity. This supports Pan’s (1923) observation that “modern urbanization has had so many dysgenic effects upon the race.”