Forrester used his Urban Dynamics model to tell the US Congress in 1970 that low-income housing programs worsen, rather than relieve, urban poverty

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Building on his Urban Dynamics (1969) simulation, Jay Forrester testified before the US House Subcommittee on Urban Growth on October 7, 1970, arguing — in his own words from his essay "Counterintuitive Behavior of Social Systems" recounting the testimony (first published in the January 1971 Technology Review; quoted here from the March 1995 updated text, MIT OCW document D-4468-2) — that "the investigation showed how depressed areas in cities arise from excess low-income housing rather than from a commonly presumed housing shortage." A systems-dynamics model built by a computer engineer delivered a policy-reversing, "counterintuitive" recommendation directly to a national legislature: that subsidizing low-income housing was making the urban poverty it targeted worse, not better.

This is the same methodological family — and the same rhetorical shape, a systems model overturning conventional policy wisdom — that the vault already documents Song Jian applying to China's fertility rate eight years later; see claim-forrester-1970-club-of-rome-conference-produced-world-dynamics for the shared Club-of-Rome lineage connecting the two cases. Karen Jarzynka's 2006 University at Albany master's essay, circulated as supplementary material in the System Dynamics Society's 2006 conference proceedings (Tier 3), confirms Urban Dynamics was highly criticized on publication amid US urban unrest ("race riots, high crime rates, high unemployment" — a reception she reads as "a question of timing"), and tests real housing programs (HOPE VI, Section 8) against her own modified version of Forrester's model — one later researcher's critical model-based evaluation, evidence of a contested academic afterlife rather than of any traceable policy trigger. A more direct hypothesis — that Urban Dynamics supplied the technical legitimation for New York City's 1976 "planned shrinkage" disinvestment policy (Housing Commissioner Roger Starr) — was checked this session and did not hold up: on WebSearch snippets only, Starr's theory traces to his 1966 book Urban Choices, three years before Urban Dynamics existed. That timeline claim was seen only via secondary summaries, not independently fetched, and is recorded here only as a checked-and-unconfirmed lead, [unverified-historical — Starr/Urban Dynamics timeline seen only via WebSearch snippets, needs primary], not as a claim in its own right.