Even generous population estimate errors leave PTA membership declines intact

Evidence

Although these 1900–50 estimates are imprecise, they do not affect the basic pattern in figure 9. For example, public school enrollment in 1935 was somewhat more than 26 million; my method generated an estimate of 21 million families, for a PTA membership rate of eight. It is utterly implausible that the actual number of families was more than 25 million or less than 15 million, which gives bounds of seven and eleven for the PTA membership rate. — Robert D. Putnam, Bowling Alone The Collapse and Revival…, 1573

Categorization

• XREF: Shows Putnam’s own robustness-checking style, relevant to how credible his larger social-capital decline claims are. — connects to: Foreign membership growth can distort apparent US civic association trends — Robert D. Putnam, Bowling Alone The Collapse and Revival…, 1572

Broader Connections

• Foreign membership growth can distort apparent US civic association trends #corroborates (0.85) — Robert D. Putnam, Bowling Alone The Collapse and Revival…, 1572