To date our understanding of the factors affecting the housing supply stem from the private provision of new units through real estate development. This paper investigates a different aspect of housing supply, the private provision of rental housing through investment in existing properties. Using logistic regression and a series of micro datasets of Australian households we examine the investment decision of residential rental property investors over the period 1990 – 2004. The sample period incorporates a full real estate cycle. Our results indicate that wealth-related factors are the dominant factors driving these investments. Life-cycle factors such as marriage and children play a less important role. Most of the determinants of income property investment do not vary with the property cycle. Marriage is an exception. It became more important as house prices rose.