Public-Data

Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. Give every cohort the same completed fertility and let each one postpone by d years relative to the last. The period TFR is then exactly Q/(1+d), the period mean age of childbearing rises at d/(1+d) rather than at d, and dividing the first by one minus the second returns Q to five decimal places — the Bongaarts-Feeney adjustment, which on this schedule is an identity rather than a correction....

Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. Give every worker a universal raise of g and hire entrants below the median. The median slides m/2 ranks, order statistics near the median are spaced 1/(n f(M)) apart, so the median falls once the entry share passes 2 g M f(M) - which for a lognormal is 0....

Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. Take one lognormal population and distort it twice: the poorest tenth loses 90% of its income, or the richest hundredth has its income multiplied by 2.51. Tuned to the same Gini, both land on 0....