House price to income calculations

Today's Stuff column looks at different scenarios for returning New Zealand house prices to an affordable ratio of three times median incomes. The calculations underpinning these scenarios are here. The spreadsheet has five tabs representing five different scenarios for house prices: plateauing, rising more slowly than inflation, falling slowly, undergoing a sharp correction, and crashing. Each scenario makes assumptions about increases to median incomes, a possible one-year decrease in prices, and a possible gradual long-term decrease in prices. Users can enter their own assumptions to generate their own scenarios.