Using transactions data on apartment sales in Sweden, and taking in consideration the decision made by Swedish Riksbank, we examined the effect of mandatory mortgage amortization on apartment prices. In addition, we examined the effect on apartment demand preferences. For this purpose, we created indices of apartment prices using traditional hedonic models. We applied the spatial model in estimating a zone level apartment price index. With the created indices, we studied the effect on apartment prices by using the traditional panel data method. The propensity score model was used to analyze the effect of the decision on the property prices. We applied different time periods as the event window (quarter, 2 quarters, 1 year, 2 years). Finally, we tested several cut-off time points. We found no effect of the Riksbank decision on apartment prices, however we found a change in apartment preferences.