Can internet ads serve as an indicator of homeownership rates?

In this paper, we propose an indicator of the homeownership rate based on Internet ads offering the housing for rent and sale. We constructed the HOR estimate using the number of ads in four different markets (flats for rent, flats for sale, houses for rent, and houses for sale). Our HOR indicator was tested using data of German NUTS1 and planning (ROR) regions. The correlation between our estimate of the HOR and the alternative HOR figures varies between 0.834 and 0.874 at NUTS1 level and is 0.761 at the ROR level. All correlation coefficients are statistically significant. Our HOR estimate is particularly highly correlated with the official HOR figures. Thus, it is shown that our Internet-based indices could serve as a good indicator of the homeownership rate in German regions.