Source
http://www.demographia.com/db-dhi-index.htm — original source (opens in a new tab; the file is not redistributed)
Context: thesis · Feeds: none
Summary
Annual survey of housing affordability across 95 major markets in 8 nations (Australia, Canada, China–HK, Ireland, NZ, Singapore, UK, USA) using the median multiple (median house price ÷ median household income) as the primary metric. Rates markets on a 4-point scale: ≤3.0 affordable, 3.1–4.0 moderately unaffordable, 4.1–5.0 seriously unaffordable, 5.1+ severely unaffordable. 2025 edition uses Q3 2024 data. No market in the 8-nation survey is currently affordable. Argues urban containment policies (greenbelts, urban growth boundaries) as the primary structural driver of unaffordability. NZ is represented by Auckland only.
Key thesis insights
- NZ housing unaffordability benchmark: Auckland median multiple = 7.7 (Q3 2024, severely unaffordable). This is the primary quantitative comparator for the NZ housing crisis in thesis chapters on community housing demand. RD_002
- Historical trajectory: NZ median multiples were approximately 2.8 in the early 1990s — within the affordable range — and have risen to 7.7 over 30 years, tracking the same period as the government capital withdrawal documented in ot_002_carroll-2019-community-housing-nz. RD_002
- Pre-pandemic to post-pandemic improvement: Auckland peaked at 8.6 (pre-pandemic 2019), declined post-COVID, and stands at 7.7 in 2024 — an improvement, but still severely unaffordable; suggests cyclical volatility rather than structural resolution. RD_002
- Counterurbanization as structural pressure: Middle-income households in severely unaffordable markets are relocating to lower-cost markets — a pattern that reinforces the case for intentional community models in lower-density rural/peri-urban settings as an affordability pathway. RD_002
- Policy contrast: Singapore achieves 90%+ homeownership through its HDB public housing model — provided as a positive case study that deliberate housing policy (not just market forces) can produce affordable outcomes at scale. RD_002
Connections
Links to
Sources (1): OT_002