The document summarizes a study examining the relationship between housing prices, rents, investments, and Tobin's q in the German housing market. Panel regressions showed that Tobin's q explained around 20% of investment fluctuations overall, and up to 49% for major cities. Individual regressions found that Tobin's q strongly correlated with building activity in around half of cities, and expanding the analysis to surrounding counties improved explanatory power in most cases. In conclusion, while Tobin's q influenced investments, correlations were less clear than expected theoretically, and demand for construction was often not contained within city limits alone.