CALIBRATION OF BORROWER-BASED MACROPRUDENTIAL MEASURES FOR MORTGAGE EXPOSURES: RIGOROUS APPROACH AND ITS APPLICATION TO THE CZECH REPUBLIC

Although the use of residential real estate macroprudential tools has become common in recent years, rigorous approaches to their calibration have been relatively scarce. The goal of this paper is to present an approach to (i) evaluating direct risks to financial stability related to residential real estate exposures, and to (ii) calibrating borrower-based macroprudential measures. First we present a macroprudential indicator of potential losses related to the provision of new mortgage loans. Then we show how to determine risky values of the loan-to-value, loan-to-income and loan service-to-income ratios by performing stress tests on the individual new mortgage loans. Finally, we demonstrate the applicability of this approach on the case of the Czech Republic. We conclude by showing that simultaneous adoption of several macroprudential measures may enhance their efficiency without imposing higher restrictions on the mortgage market.