A synthesis citing both Greenhalgh and Liang Zhongtang frames Song Jian's contribution as supplying scientific legitimation for an already-desired stricter policy, not originating the political desire

chinapopulation-policyone-child-policycyberneticshistoriographycontested-causationcold-war-science

Whyte, Wang, and Cai draw on both Greenhalgh and Liang Zhongtang to answer why the more coercive one-child policy launched, given that leadership already had a more restrictive birth-control program underway (see claim-china-leadership-contemplated-one-child-policy-1978-before-song): "Even more ambitious official fertility control targets found a ready and purportedly scientific rationale after 1979 in demographic projections produced by a small group of scientists headed by Song Jian, who were influenced by the Club of Rome's Limits to Growth and other Western doomsday writings in the 1970s." Footnote 24 describes Song as using "his access to computers and his political connections to increasingly dominate debates among professional demographers about China's population policy, as described by Greenhalgh and Liang" — i.e., even a source citing Liang's book alongside Greenhalgh's does not use Liang to erase Song's role, but to describe it more precisely: Song dominated the technical debate and supplied legitimating rationale, against a leadership that already wanted a more restrictive policy than the 1970s campaign.

This is corroborating, independent triangulation — different authors, different venue, published a decade after Greenhalgh — of the "leadership already inclined toward strict control" half of the original disputed question, while leaving Song's role in shaping the policy's unusually extreme form intact rather than refuted.