Spatial–Temporal Evolution Patterns and Influencing Factors of China’s Urban Housing Price-to-Income Ratio

The housing price-to-income ratio (PIR) is an important indicator for measuring the health of the real estate market and detecting residents’ housing affordability. Including data of 336 cities in China from 2009 to 2020 as the research unit, the PIR’s spatial and temporal evolution characteristics are explored by using the urban rank-size rule and Markov chain, and its influencing factors are explored using the random forest model. The results show the following: (1) The PIR is in a normal distribution pattern, and there was a significant positive spatial correlation, which tended to increase. (2) Spatially, the PIR shows an overall distribution trend of “high in the east and low in the west”, and a rising trend of fluctuation is shown in the average PIR. (3) The PIR’s time evolution has high stability. China’s urban PIR is primarily the stable type from 2009 to 2015 and mainly the upward transfer type from 2015 to 2020. (4) The influence of economic, demographic, social, and expected factors on the PIR decreases, among which real estate investment density, industrial structure level, residents’ consumption level, and real estate activity are the dominant factors enhancing trends and showing a complex nonlinear relationship.