Demographic Transformation and Structural Evolution of Greater Sydney (1970–2025): A Structured Dataset for Comparative Urban Public Policy Analysis

Abstract

This paper constructs a high-resolution longitudinal demographic dataset for Greater Sydney, spanning from the post-war industrial era (1970) to current projections (2025). The study structures variables including total population, age-specific cohorts, and sex-disaggregated data to provide a benchmark model for evaluating large-scale public cultural infrastructure. By comparing the demographic “carrying capacity” of Sydney during the 1973 Opera House inauguration with the context of Sendai City’s music hall project in 2026, this research identifies critical structural differences in urban sustainability. The findings highlight Sydney’s transition from an internal growth model to an immigration-dependent maturation model, offering vital insights for modern fiscal and operational validity assessments in public policy.

Position of the Researcher and Conflict of Interest

The author, Tohoku I-ST, is an independent citizen researcher. This research was conducted to contribute to public evidence-based discourse on urban planning in regional Japan. The author declares no conflicts of interest and has received no external funding.